Search Results: "nsl"

13 April 2024

Paul Tagliamonte: Domo Arigato, Mr. debugfs

Years ago, at what I think I remember was DebConf 15, I hacked for a while on debhelper to write build-ids to debian binary control files, so that the build-id (more specifically, the ELF note .note.gnu.build-id) wound up in the Debian apt archive metadata. I ve always thought this was super cool, and seeing as how Michael Stapelberg blogged some great pointers around the ecosystem, including the fancy new debuginfod service, and the find-dbgsym-packages helper, which uses these same headers, I don t think I m the only one. At work I ve been using a lot of rust, specifically, async rust using tokio. To try and work on my style, and to dig deeper into the how and why of the decisions made in these frameworks, I ve decided to hack up a project that I ve wanted to do ever since 2015 write a debug filesystem. Let s get to it.

Back to the Future Time to admit something. I really love Plan 9. It s just so good. So many ideas from Plan 9 are just so prescient, and everything just feels right. Not just right like, feels good like, correct. The bit that I ve always liked the most is 9p, the network protocol for serving a filesystem over a network. This leads to all sorts of fun programs, like the Plan 9 ftp client being a 9p server you mount the ftp server and access files like any other files. It s kinda like if fuse were more fully a part of how the operating system worked, but fuse is all running client-side. With 9p there s a single client, and different servers that you can connect to, which may be backed by a hard drive, remote resources over something like SFTP, FTP, HTTP or even purely synthetic. The interesting (maybe sad?) part here is that 9p wound up outliving Plan 9 in terms of adoption 9p is in all sorts of places folks don t usually expect. For instance, the Windows Subsystem for Linux uses the 9p protocol to share files between Windows and Linux. ChromeOS uses it to share files with Crostini, and qemu uses 9p (virtio-p9) to share files between guest and host. If you re noticing a pattern here, you d be right; for some reason 9p is the go-to protocol to exchange files between hypervisor and guest. Why? I have no idea, except maybe due to being designed well, simple to implement, and it s a lot easier to validate the data being shared and validate security boundaries. Simplicity has its value. As a result, there s a lot of lingering 9p support kicking around. Turns out Linux can even handle mounting 9p filesystems out of the box. This means that I can deploy a filesystem to my LAN or my localhost by running a process on top of a computer that needs nothing special, and mount it over the network on an unmodified machine unlike fuse, where you d need client-specific software to run in order to mount the directory. For instance, let s mount a 9p filesystem running on my localhost machine, serving requests on 127.0.0.1:564 (tcp) that goes by the name mountpointname to /mnt.
$ mount -t 9p \
-o trans=tcp,port=564,version=9p2000.u,aname=mountpointname \
127.0.0.1 \
/mnt
Linux will mount away, and attach to the filesystem as the root user, and by default, attach to that mountpoint again for each local user that attempts to use it. Nifty, right? I think so. The server is able to keep track of per-user access and authorization along with the host OS.

WHEREIN I STYX WITH IT Since I wanted to push myself a bit more with rust and tokio specifically, I opted to implement the whole stack myself, without third party libraries on the critical path where I could avoid it. The 9p protocol (sometimes called Styx, the original name for it) is incredibly simple. It s a series of client to server requests, which receive a server to client response. These are, respectively, T messages, which transmit a request to the server, which trigger an R message in response (Reply messages). These messages are TLV payload with a very straight forward structure so straight forward, in fact, that I was able to implement a working server off nothing more than a handful of man pages. Later on after the basics worked, I found a more complete spec page that contains more information about the unix specific variant that I opted to use (9P2000.u rather than 9P2000) due to the level of Linux specific support for the 9P2000.u variant over the 9P2000 protocol.

MR ROBOTO The backend stack over at zoo is rust and tokio running i/o for an HTTP and WebRTC server. I figured I d pick something fairly similar to write my filesystem with, since 9P can be implemented on basically anything with I/O. That means tokio tcp server bits, which construct and use a 9p server, which has an idiomatic Rusty API that partially abstracts the raw R and T messages, but not so much as to cause issues with hiding implementation possibilities. At each abstraction level, there s an escape hatch allowing someone to implement any of the layers if required. I called this framework arigato which can be found over on docs.rs and crates.io.
/// Simplified version of the arigato File trait; this isn't actually
/// the same trait; there's some small cosmetic differences. The
/// actual trait can be found at:
///
/// https://docs.rs/arigato/latest/arigato/server/trait.File.html
trait File  
/// OpenFile is the type returned by this File via an Open call.
 type OpenFile: OpenFile;
/// Return the 9p Qid for this file. A file is the same if the Qid is
 /// the same. A Qid contains information about the mode of the file,
 /// version of the file, and a unique 64 bit identifier.
 fn qid(&self) -> Qid;
/// Construct the 9p Stat struct with metadata about a file.
 async fn stat(&self) -> FileResult<Stat>;
/// Attempt to update the file metadata.
 async fn wstat(&mut self, s: &Stat) -> FileResult<()>;
/// Traverse the filesystem tree.
 async fn walk(&self, path: &[&str]) -> FileResult<(Option<Self>, Vec<Self>)>;
/// Request that a file's reference be removed from the file tree.
 async fn unlink(&mut self) -> FileResult<()>;
/// Create a file at a specific location in the file tree.
 async fn create(
&mut self,
name: &str,
perm: u16,
ty: FileType,
mode: OpenMode,
extension: &str,
) -> FileResult<Self>;
/// Open the File, returning a handle to the open file, which handles
 /// file i/o. This is split into a second type since it is genuinely
 /// unrelated -- and the fact that a file is Open or Closed can be
 /// handled by the  arigato  server for us.
 async fn open(&mut self, mode: OpenMode) -> FileResult<Self::OpenFile>;
 
/// Simplified version of the arigato OpenFile trait; this isn't actually
/// the same trait; there's some small cosmetic differences. The
/// actual trait can be found at:
///
/// https://docs.rs/arigato/latest/arigato/server/trait.OpenFile.html
trait OpenFile  
/// iounit to report for this file. The iounit reported is used for Read
 /// or Write operations to signal, if non-zero, the maximum size that is
 /// guaranteed to be transferred atomically.
 fn iounit(&self) -> u32;
/// Read some number of bytes up to  buf.len()  from the provided
 ///  offset  of the underlying file. The number of bytes read is
 /// returned.
 async fn read_at(
&mut self,
buf: &mut [u8],
offset: u64,
) -> FileResult<u32>;
/// Write some number of bytes up to  buf.len()  from the provided
 ///  offset  of the underlying file. The number of bytes written
 /// is returned.
 fn write_at(
&mut self,
buf: &mut [u8],
offset: u64,
) -> FileResult<u32>;
 

Thanks, decade ago paultag! Let s do it! Let s use arigato to implement a 9p filesystem we ll call debugfs that will serve all the debug files shipped according to the Packages metadata from the apt archive. We ll fetch the Packages file and construct a filesystem based on the reported Build-Id entries. For those who don t know much about how an apt repo works, here s the 2-second crash course on what we re doing. The first is to fetch the Packages file, which is specific to a binary architecture (such as amd64, arm64 or riscv64). That architecture is specific to a component (such as main, contrib or non-free). That component is specific to a suite, such as stable, unstable or any of its aliases (bullseye, bookworm, etc). Let s take a look at the Packages.xz file for the unstable-debug suite, main component, for all amd64 binaries.
$ curl \
https://deb.debian.org/debian-debug/dists/unstable-debug/main/binary-amd64/Packages.xz \
  unxz
This will return the Debian-style rfc2822-like headers, which is an export of the metadata contained inside each .deb file which apt (or other tools that can use the apt repo format) use to fetch information about debs. Let s take a look at the debug headers for the netlabel-tools package in unstable which is a package named netlabel-tools-dbgsym in unstable-debug.
Package: netlabel-tools-dbgsym
Source: netlabel-tools (0.30.0-1)
Version: 0.30.0-1+b1
Installed-Size: 79
Maintainer: Paul Tagliamonte <paultag@debian.org>
Architecture: amd64
Depends: netlabel-tools (= 0.30.0-1+b1)
Description: debug symbols for netlabel-tools
Auto-Built-Package: debug-symbols
Build-Ids: e59f81f6573dadd5d95a6e4474d9388ab2777e2a
Description-md5: a0e587a0cf730c88a4010f78562e6db7
Section: debug
Priority: optional
Filename: pool/main/n/netlabel-tools/netlabel-tools-dbgsym_0.30.0-1+b1_amd64.deb
Size: 62776
SHA256: 0e9bdb087617f0350995a84fb9aa84541bc4df45c6cd717f2157aa83711d0c60
So here, we can parse the package headers in the Packages.xz file, and store, for each Build-Id, the Filename where we can fetch the .deb at. Each .deb contains a number of files but we re only really interested in the files inside the .deb located at or under /usr/lib/debug/.build-id/, which you can find in debugfs under rfc822.rs. It s crude, and very single-purpose, but I m feeling a bit lazy.

Who needs dpkg?! For folks who haven t seen it yet, a .deb file is a special type of .ar file, that contains (usually) three files inside debian-binary, control.tar.xz and data.tar.xz. The core of an .ar file is a fixed size (60 byte) entry header, followed by the specified size number of bytes.
[8 byte .ar file magic]
[60 byte entry header]
[N bytes of data]
[60 byte entry header]
[N bytes of data]
[60 byte entry header]
[N bytes of data]
...
First up was to implement a basic ar parser in ar.rs. Before we get into using it to parse a deb, as a quick diversion, let s break apart a .deb file by hand something that is a bit of a rite of passage (or at least it used to be? I m getting old) during the Debian nm (new member) process, to take a look at where exactly the .debug file lives inside the .deb file.
$ ar x netlabel-tools-dbgsym_0.30.0-1+b1_amd64.deb
$ ls
control.tar.xz debian-binary
data.tar.xz netlabel-tools-dbgsym_0.30.0-1+b1_amd64.deb
$ tar --list -f data.tar.xz   grep '.debug$'
./usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
Since we know quite a bit about the structure of a .deb file, and I had to implement support from scratch anyway, I opted to implement a (very!) basic debfile parser using HTTP Range requests. HTTP Range requests, if supported by the server (denoted by a accept-ranges: bytes HTTP header in response to an HTTP HEAD request to that file) means that we can add a header such as range: bytes=8-68 to specifically request that the returned GET body be the byte range provided (in the above case, the bytes starting from byte offset 8 until byte offset 68). This means we can fetch just the ar file entry from the .deb file until we get to the file inside the .deb we are interested in (in our case, the data.tar.xz file) at which point we can request the body of that file with a final range request. I wound up writing a struct to handle a read_at-style API surface in hrange.rs, which we can pair with ar.rs above and start to find our data in the .deb remotely without downloading and unpacking the .deb at all. After we have the body of the data.tar.xz coming back through the HTTP response, we get to pipe it through an xz decompressor (this kinda sucked in Rust, since a tokio AsyncRead is not the same as an http Body response is not the same as std::io::Read, is not the same as an async (or sync) Iterator is not the same as what the xz2 crate expects; leading me to read blocks of data to a buffer and stuff them through the decoder by looping over the buffer for each lzma2 packet in a loop), and tarfile parser (similarly troublesome). From there we get to iterate over all entries in the tarfile, stopping when we reach our file of interest. Since we can t seek, but gdb needs to, we ll pull it out of the stream into a Cursor<Vec<u8>> in-memory and pass a handle to it back to the user. From here on out its a matter of gluing together a File traited struct in debugfs, and serving the filesystem over TCP using arigato. Done deal!

A quick diversion about compression I was originally hoping to avoid transferring the whole tar file over the network (and therefore also reading the whole debug file into ram, which objectively sucks), but quickly hit issues with figuring out a way around seeking around an xz file. What s interesting is xz has a great primitive to solve this specific problem (specifically, use a block size that allows you to seek to the block as close to your desired seek position just before it, only discarding at most block size - 1 bytes), but data.tar.xz files generated by dpkg appear to have a single mega-huge block for the whole file. I don t know why I would have expected any different, in retrospect. That means that this now devolves into the base case of How do I seek around an lzma2 compressed data stream ; which is a lot more complex of a question. Thankfully, notoriously brilliant tianon was nice enough to introduce me to Jon Johnson who did something super similar adapted a technique to seek inside a compressed gzip file, which lets his service oci.dag.dev seek through Docker container images super fast based on some prior work such as soci-snapshotter, gztool, and zran.c. He also pulled this party trick off for apk based distros over at apk.dag.dev, which seems apropos. Jon was nice enough to publish a lot of his work on this specifically in a central place under the name targz on his GitHub, which has been a ton of fun to read through. The gist is that, by dumping the decompressor s state (window of previous bytes, in-memory data derived from the last N-1 bytes) at specific checkpoints along with the compressed data stream offset in bytes and decompressed offset in bytes, one can seek to that checkpoint in the compressed stream and pick up where you left off creating a similar block mechanism against the wishes of gzip. It means you d need to do an O(n) run over the file, but every request after that will be sped up according to the number of checkpoints you ve taken. Given the complexity of xz and lzma2, I don t think this is possible for me at the moment especially given most of the files I ll be requesting will not be loaded from again especially when I can just cache the debug header by Build-Id. I want to implement this (because I m generally curious and Jon has a way of getting someone excited about compression schemes, which is not a sentence I thought I d ever say out loud), but for now I m going to move on without this optimization. Such a shame, since it kills a lot of the work that went into seeking around the .deb file in the first place, given the debian-binary and control.tar.gz members are so small.

The Good First, the good news right? It works! That s pretty cool. I m positive my younger self would be amused and happy to see this working; as is current day paultag. Let s take debugfs out for a spin! First, we need to mount the filesystem. It even works on an entirely unmodified, stock Debian box on my LAN, which is huge. Let s take it for a spin:
$ mount \
-t 9p \
-o trans=tcp,version=9p2000.u,aname=unstable-debug \
192.168.0.2 \
/usr/lib/debug/.build-id/
And, let s prove to ourselves that this actually mounted before we go trying to use it:
$ mount   grep build-id
192.168.0.2 on /usr/lib/debug/.build-id type 9p (rw,relatime,aname=unstable-debug,access=user,trans=tcp,version=9p2000.u,port=564)
Slick. We ve got an open connection to the server, where our host will keep a connection alive as root, attached to the filesystem provided in aname. Let s take a look at it.
$ ls /usr/lib/debug/.build-id/
00 0d 1a 27 34 41 4e 5b 68 75 82 8E 9b a8 b5 c2 CE db e7 f3
01 0e 1b 28 35 42 4f 5c 69 76 83 8f 9c a9 b6 c3 cf dc E7 f4
02 0f 1c 29 36 43 50 5d 6a 77 84 90 9d aa b7 c4 d0 dd e8 f5
03 10 1d 2a 37 44 51 5e 6b 78 85 91 9e ab b8 c5 d1 de e9 f6
04 11 1e 2b 38 45 52 5f 6c 79 86 92 9f ac b9 c6 d2 df ea f7
05 12 1f 2c 39 46 53 60 6d 7a 87 93 a0 ad ba c7 d3 e0 eb f8
06 13 20 2d 3a 47 54 61 6e 7b 88 94 a1 ae bb c8 d4 e1 ec f9
07 14 21 2e 3b 48 55 62 6f 7c 89 95 a2 af bc c9 d5 e2 ed fa
08 15 22 2f 3c 49 56 63 70 7d 8a 96 a3 b0 bd ca d6 e3 ee fb
09 16 23 30 3d 4a 57 64 71 7e 8b 97 a4 b1 be cb d7 e4 ef fc
0a 17 24 31 3e 4b 58 65 72 7f 8c 98 a5 b2 bf cc d8 E4 f0 fd
0b 18 25 32 3f 4c 59 66 73 80 8d 99 a6 b3 c0 cd d9 e5 f1 fe
0c 19 26 33 40 4d 5a 67 74 81 8e 9a a7 b4 c1 ce da e6 f2 ff
Outstanding. Let s try using gdb to debug a binary that was provided by the Debian archive, and see if it ll load the ELF by build-id from the right .deb in the unstable-debug suite:
$ gdb -q /usr/sbin/netlabelctl
Reading symbols from /usr/sbin/netlabelctl...
Reading symbols from /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug...
(gdb)
Yes! Yes it will!
$ file /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
/usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter *empty*, BuildID[sha1]=e59f81f6573dadd5d95a6e4474d9388ab2777e2a, for GNU/Linux 3.2.0, with debug_info, not stripped

The Bad Linux s support for 9p is mainline, which is great, but it s not robust. Network issues or server restarts will wedge the mountpoint (Linux can t reconnect when the tcp connection breaks), and things that work fine on local filesystems get translated in a way that causes a lot of network chatter for instance, just due to the way the syscalls are translated, doing an ls, will result in a stat call for each file in the directory, even though linux had just got a stat entry for every file while it was resolving directory names. On top of that, Linux will serialize all I/O with the server, so there s no concurrent requests for file information, writes, or reads pending at the same time to the server; and read and write throughput will degrade as latency increases due to increasing round-trip time, even though there are offsets included in the read and write calls. It works well enough, but is frustrating to run up against, since there s not a lot you can do server-side to help with this beyond implementing the 9P2000.L variant (which, maybe is worth it).

The Ugly Unfortunately, we don t know the file size(s) until we ve actually opened the underlying tar file and found the correct member, so for most files, we don t know the real size to report when getting a stat. We can t parse the tarfiles for every stat call, since that d make ls even slower (bummer). Only hiccup is that when I report a filesize of zero, gdb throws a bit of a fit; let s try with a size of 0 to start:
$ ls -lah /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
-r--r--r-- 1 root root 0 Dec 31 1969 /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
$ gdb -q /usr/sbin/netlabelctl
Reading symbols from /usr/sbin/netlabelctl...
Reading symbols from /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug...
warning: Discarding section .note.gnu.build-id which has a section size (24) larger than the file size [in module /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug]
[...]
This obviously won t work since gdb will throw away all our hard work because of stat s output, and neither will loading the real size of the underlying file. That only leaves us with hardcoding a file size and hope nothing else breaks significantly as a result. Let s try it again:
$ ls -lah /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
-r--r--r-- 1 root root 954M Dec 31 1969 /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug
$ gdb -q /usr/sbin/netlabelctl
Reading symbols from /usr/sbin/netlabelctl...
Reading symbols from /usr/lib/debug/.build-id/e5/9f81f6573dadd5d95a6e4474d9388ab2777e2a.debug...
(gdb)
Much better. I mean, terrible but better. Better for now, anyway.

Kilroy was here Do I think this is a particularly good idea? I mean; kinda. I m probably going to make some fun 9p arigato-based filesystems for use around my LAN, but I don t think I ll be moving to use debugfs until I can figure out how to ensure the connection is more resilient to changing networks, server restarts and fixes on i/o performance. I think it was a useful exercise and is a pretty great hack, but I don t think this ll be shipping anywhere anytime soon. Along with me publishing this post, I ve pushed up all my repos; so you should be able to play along at home! There s a lot more work to be done on arigato; but it does handshake and successfully export a working 9P2000.u filesystem. Check it out on on my github at arigato, debugfs and also on crates.io and docs.rs. At least I can say I was here and I got it working after all these years.

1 April 2024

Colin Watson: Free software activity in March 2024

My Debian contributions this month were all sponsored by Freexian.

Simon Josefsson: Towards reproducible minimal source code tarballs? On *-src.tar.gz

While the work to analyze the xz backdoor is in progress, several ideas have been suggested to improve the software supply chain ecosystem. Some of those ideas are good, some of the ideas are at best irrelevant and harmless, and some suggestions are plain bad. I d like to attempt to formalize two ideas, which have been discussed before, but the context in which they can be appreciated have not been as clear as it is today.
  1. Reproducible tarballs. The idea is that published source tarballs should be possible to reproduce independently somehow, and that this should be continuously tested and verified preferrably as part of the upstream project continuous integration system (e.g., GitHub action or GitLab pipeline). While nominally this looks easy to achieve, there are some complex matters in this, for example: what timestamps to use for files in the tarball? I ve brought up this aspect before.
  2. Minimal source tarballs without generated vendor files. Most GNU Autoconf/Automake-based tarballs pre-generated files which are important for bootstrapping on exotic systems that does not have the required dependencies. For the bootstrapping story to succeed, this approach is important to support. However it has become clear that this practice raise significant costs and risks. Most modern GNU/Linux distributions have all the required dependencies and actually prefers to re-build everything from source code. These pre-generated extra files introduce uncertainty to that process.
My strawman proposal to improve things is to define new tarball format *-src.tar.gz with at least the following properties:
  1. The tarball should allow users to build the project, which is the entire purpose of all this. This means that at least all source code for the project has to be included.
  2. The tarballs should be signed, for example with PGP or minisign.
  3. The tarball should be possible to reproduce bit-by-bit by a third party using upstream s version controlled sources and a pointer to which revision was used (e.g., git tag or git commit).
  4. The tarball should not require an Internet connection to download things.
    • Corollary: every external dependency either has to be explicitly documented as such (e.g., gcc and GnuTLS), or included in the tarball.
    • Observation: This means including all *.po gettext translations which are normally downloaded when building from version controlled sources.
  5. The tarball should contain everything required to build the project from source using as much externally released versioned tooling as possible. This is the minimal property lacking today.
    • Corollary: This means including a vendored copy of OpenSSL or libz is not acceptable: link to them as external projects.
    • Open question: How about non-released external tooling such as gnulib or autoconf archive macros? This is a bit more delicate: most distributions either just package one current version of gnulib or autoconf archive, not previous versions. While this could change, and distributions could package the gnulib git repository (up to some current version) and the autoconf archive git repository and packages were set up to extract the version they need (gnulib s ./bootstrap already supports this via the gnulib-refdir parameter), this is not normally in place.
    • Suggested Corollary: The tarball should contain content from git submodule s such as gnulib and the necessary Autoconf archive M4 macros required by the project.
  6. Similar to how the GNU project specify the ./configure interface we need a documented interface for how to bootstrap the project. I suggest to use the already well established idiom of running ./bootstrap to set up the package to later be able to be built via ./configure. Of course, some projects are not using the autotool ./configure interface and will not follow this aspect either, but like most build systems that compete with autotools have instructions on how to build the project, they should document similar interfaces for bootstrapping the source tarball to allow building.
If tarballs that achieve the above goals were available from popular upstream projects, distributions could more easily use them instead of current tarballs that include pre-generated content. The advantage would be that the build process is not tainted by unnecessary files. We need to develop tools for maintainers to create these tarballs, similar to make dist that generate today s foo-1.2.3.tar.gz files. I think one common argument against this approach will be: Why bother with all that, and just use git-archive outputs? Or avoid the entire tarball approach and move directly towards version controlled check outs and referring to upstream releases as git URL and commit tag or id. One problem with this is that SHA-1 is broken, so placing trust in a SHA-1 identifier is simply not secure. Another counter-argument is that this optimize for packagers benefits at the cost of upstream maintainers: most upstream maintainers do not want to store gettext *.po translations in their source code repository. A compromise between the needs of maintainers and packagers is useful, so this *-src.tar.gz tarball approach is the indirection we need to solve that. Update: In my experiment with source-only tarballs for Libntlm I actually did use git-archive output. What do you think?

4 March 2024

Paulo Henrique de Lima Santana: Bits from FOSDEM 2023 and 2024

Link para vers o em portugu s

Intro Since 2019, I have traveled to Brussels at the beginning of the year to join FOSDEM, considered the largest and most important Free Software event in Europe. The 2024 edition was the fourth in-person edition in a row that I joined (2021 and 2022 did not happen due to COVID-19) and always with the financial help of Debian, which kindly paid my flight tickets after receiving my request asking for help to travel and approved by the Debian leader. In 2020 I wrote several posts with a very complete report of the days I spent in Brussels. But in 2023 I didn t write anything, and becayse last year and this year I coordinated a room dedicated to translations of Free Software and Open Source projects, I m going to take the opportunity to write about these two years and how it was my experience. After my first trip to FOSDEM, I started to think that I could join in a more active way than just a regular attendee, so I had the desire to propose a talk to one of the rooms. But then I thought that instead of proposing a tal, I could organize a room for talks :-) and with the topic translations which is something that I m very interested in, because it s been a few years since I ve been helping to translate the Debian for Portuguese.

Joining FOSDEM 2023 In the second half of 2022 I did some research and saw that there had never been a room dedicated to translations, so when the FOSDEM organization opened the call to receive room proposals (called DevRoom) for the 2023 edition, I sent a proposal to a translation room and it was accepted! After the room was confirmed, the next step was for me, as room coordinator, to publicize the call for talk proposals. I spent a few weeks hoping to find out if I would receive a good number of proposals or if it would be a failure. But to my happiness, I received eight proposals and I had to select six to schedule the room programming schedule due to time constraints . FOSDEM 2023 took place from February 4th to 5th and the translation devroom was scheduled on the second day in the afternoon. Fosdem 2023 The talks held in the room were these below, and in each of them you can watch the recording video. And on the first day of FOSDEM I was at the Debian stand selling the t-shirts that I had taken from Brazil. People from France were also there selling other products and it was cool to interact with people who visited the booth to buy and/or talk about Debian.
Fosdem 2023

Fosdem 2023
Photos

Joining FOSDEM 2024 The 2023 result motivated me to propose the translation devroom again when the FOSDEM 2024 organization opened the call for rooms . I was waiting to find out if the FOSDEM organization would accept a room on this topic for the second year in a row and to my delight, my proposal was accepted again :-) This time I received 11 proposals! And again due to time constraints, I had to select six to schedule the room schedule grid. FOSDEM 2024 took place from February 3rd to 4th and the translation devroom was scheduled for the second day again, but this time in the morning. The talks held in the room were these below, and in each of them you can watch the recording video. This time I didn t help at the Debian stand because I couldn t bring t-shirts to sell from Brazil. So I just stopped by and talked to some people who were there like some DDs. But I volunteered for a few hours to operate the streaming camera in one of the main rooms.
Fosdem 2024

Fosdem 2024
Photos

Conclusion The topics of the talks in these two years were quite diverse, and all the lectures were really very good. In the 12 talks we can see how translations happen in some projects such as KDE, PostgreSQL, Debian and Mattermost. We had the presentation of tools such as LibreTranslate, Weblate, scripts, AI, data model. And also reports on the work carried out by communities in Africa, China and Indonesia. The rooms were full for some talks, a little more empty for others, but I was very satisfied with the final result of these two years. I leave my special thanks to Jonathan Carter, Debian Leader who approved my flight tickets requests so that I could join FOSDEM 2023 and 2024. This help was essential to make my trip to Brussels because flight tickets are not cheap at all. I would also like to thank my wife Jandira, who has been my travel partner :-) Bruxelas As there has been an increase in the number of proposals received, I believe that interest in the translations devroom is growing. So I intend to send the devroom proposal to FOSDEM 2025, and if it is accepted, wait for the future Debian Leader to approve helping me with the flight tickets again. We ll see.

24 February 2024

Niels Thykier: Language Server for Debian: Spellchecking

This is my third update on writing a language server for Debian packaging files, which aims at providing a better developer experience for Debian packagers. Lets go over what have done since the last report.
Semantic token support I have added support for what the Language Server Protocol (LSP) call semantic tokens. These are used to provide the editor insights into tokens of interest for users. Allegedly, this is what editors would use for syntax highlighting as well. Unfortunately, eglot (emacs) does not support semantic tokens, so I was not able to test this. There is a 3-year old PR for supporting with the last update being ~3 month basically saying "Please sign the Copyright Assignment". I pinged the GitHub issue in the hopes it will get unstuck. For good measure, I also checked if I could try it via neovim. Before installing, I read the neovim docs, which helpfully listed the features supported. Sadly, I did not spot semantic tokens among those and parked from there. That was a bit of a bummer, but I left the feature in for now. If you have an LSP capable editor that supports semantic tokens, let me know how it works for you! :)
Spellchecking Finally, I implemented something Otto was missing! :) This stared with Paul Wise reminding me that there were Python binding for the hunspell spellchecker. This enabled me to get started with a quick prototype that spellchecked the Description fields in debian/control. I also added spellchecking of comments while I was add it. The spellchecker runs with the standard en_US dictionary from hunspell-en-us, which does not have a lot of technical terms in it. Much less any of the Debian specific slang. I spend considerable time providing a "built-in" wordlist for technical and Debian specific slang to overcome this. I also made a "wordlist" for known Debian people that the spellchecker did not recognise. Said wordlist is fairly short as a proof of concept, and I fully expect it to be community maintained if the language server becomes a success. My second problem was performance. As I had suspected that spellchecking was not the fastest thing in the world. Therefore, I added a very small language server for the debian/changelog, which only supports spellchecking the textual part. Even for a small changelog of a 1000 lines, the spellchecking takes about 5 seconds, which confirmed my suspicion. With every change you do, the existing diagnostics hangs around for 5 seconds before being updated. Notably, in emacs, it seems that diagnostics gets translated into an absolute character offset, so all diagnostics after the change gets misplaced for every character you type. Now, there is little I could do to speed up hunspell. But I can, as always, cheat. The way diagnostics work in the LSP is that the server listens to a set of notifications like "document opened" or "document changed". In a response to that, the LSP can start its diagnostics scanning of the document and eventually publish all the diagnostics to the editor. The spec is quite clear that the server owns the diagnostics and the diagnostics are sent as a "notification" (that is, fire-and-forgot). Accordingly, there is nothing that prevents the server from publishing diagnostics multiple times for a single trigger. The only requirement is that the server publishes the accumulated diagnostics in every publish (that is, no delta updating). Leveraging this, I had the language server for debian/changelog scan the document and publish once for approximately every 25 typos (diagnostics) spotted. This means you quickly get your first result and that clears the obsolete diagnostics. Thereafter, you get frequent updates to the remainder of the document if you do not perform any further changes. That is, up to a predefined max of typos, so we do not overload the client for longer changelogs. If you do any changes, it resets and starts over. The only bit missing was dealing with concurrency. By default, a pygls language server is single threaded. It is not great if the language server hangs for 5 seconds everytime you type anything. Fortunately, pygls has builtin support for asyncio and threaded handlers. For now, I did an async handler that await after each line and setup some manual detection to stop an obsolete diagnostics run. This means the server will fairly quickly abandon an obsolete run. Also, as a side-effect of working on the spellchecking, I fixed multiple typos in the changelog of debputy. :)
Follow up on the "What next?" from my previous update In my previous update, I mentioned I had to finish up my python-debian changes to support getting the location of a token in a deb822 file. That was done, the MR is now filed, and is pending review. Hopefully, it will be merged and uploaded soon. :) I also submitted my proposal for a different way of handling relationship substvars to debian-devel. So far, it seems to have received only positive feedback. I hope it stays that way and we will have this feature soon. Guillem proposed to move some of this into dpkg, which might delay my plans a bit. However, it might be for the better in the long run, so I will wait a bit to see what happens on that front. :) As noted above, I managed to add debian/changelog as a support format for the language server. Even if it only does spellchecking and trimming of trailing newlines on save, it technically is a new format and therefore cross that item off my list. :D Unfortunately, I did not manage to write a linter variant that does not involve using an LSP-capable editor. So that is still pending. Instead, I submitted an MR against elpa-dpkg-dev-el to have it recognize all the fields that the debian/control LSP knows about at this time to offset the lack of semantic token support in eglot.
From here... My sprinting on this topic will soon come to an end, so I have to a bit more careful now with what tasks I open! I think I will narrow my focus to providing a batch linting interface. Ideally, with an auto-fix for some of the more mechanical issues, where this is little doubt about the answer. Additionally, I think the spellchecking will need a bit more maturing. My current code still trips on naming patterns that are "clearly" verbatim or code references like things written in CamelCase or SCREAMING_SNAKE_CASE. That gets annoying really quickly. It also trips on a lot of commands like dpkg-gencontrol, but that is harder to fix since it could have been a real word. I think those will have to be fixed people using quotes around the commands. Maybe the most popular ones will end up in the wordlist. Beyond that, I will play it by ear if I have any time left. :)

21 February 2024

Niels Thykier: Expanding on the Language Server (LSP) support for debian/control

I have spent some more time on improving my language server for debian/control. Today, I managed to provide the following features:
  • The X- style prefixes for field names are now understood and handled. This means the language server now considers XC-Package-Type the same as Package-Type.

  • More diagnostics:

    • Fields without values now trigger an error marker
    • Duplicated fields now trigger an error marker
    • Fields used in the wrong paragraph now trigger an error marker
    • Typos in field names or values now trigger a warning marker. For field names, X- style prefixes are stripped before typo detection is done.
    • The value of the Section field is now validated against a dataset of known sections and trigger a warning marker if not known.
  • The "on-save trim end of line whitespace" now works. I had a logic bug in the server side code that made it submit "no change" edits to the editor.

  • The language server now provides "hover" documentation for field names. There is a small screenshot of this below. Sadly, emacs does not support markdown or, if it does, it does not announce the support for markdown. For now, all the documentation is always in markdown format and the language server will tag it as either markdown or plaintext depending on the announced support.

  • The language server now provides quick fixes for some of the more trivial problems such as deprecated fields or typos of fields and values.

  • Added more known fields including the XS-Autobuild field for non-free packages along with a link to the relevant devref section in its hover doc.

This covers basically all my known omissions from last update except spellchecking of the Description field. An image of emacs showing documentation for the Provides field from the language server.
Spellchecking Personally, I feel spellchecking would be a very welcome addition to the current feature set. However, reviewing my options, it seems that most of the spellchecking python libraries out there are not packaged for Debian, or at least not other the name I assumed they would be. The alternative is to pipe the spellchecking to another program like aspell list. I did not test this fully, but aspell list does seem to do some input buffering that I cannot easily default (at least not in the shell). Though, either way, the logic for this will not be trivial and aspell list does not seem to include the corrections either. So best case, you would get typo markers but no suggestions for what you should have typed. Not ideal. Additionally, I am also concerned with the performance for this feature. For d/control, it will be a trivial matter in practice. However, I would be reusing this for d/changelog which is 99% free text with plenty of room for typos. For a regular linter, some slowness is acceptable as it is basically a batch tool. However, for a language server, this potentially translates into latency for your edits and that gets annoying. While it is definitely on my long term todo list, I am a bit afraid that it can easily become a time sink. Admittedly, this does annoy me, because I wanted to cross off at least one of Otto's requested features soon.
On wrap-and-sort support The other obvious request from Otto would be to automate wrap-and-sort formatting. Here, the problem is that "we" in Debian do not agree on the one true formatting of debian/control. In fact, I am fairly certain we do not even agree on whether we should all use wrap-and-sort. This implies we need a style configuration. However, if we have a style configuration per person, then you get style "ping-pong" for packages where the co-maintainers do not all have the same style configuration. Additionally, it is very likely that you are a member of multiple packaging teams or groups that all have their own unique style. Ergo, only having a personal config file is doomed to fail. The only "sane" option here that I can think of is to have or support "per package" style configuration. Something that would be committed to git, so the tooling would automatically pick up the configuration. Obviously, that is not fun for large packaging teams where you have to maintain one file per package if you want a consistent style across all packages. But it beats "style ping-pong" any day of the week. Note that I am perfectly open to having a personal configuration file as a fallback for when the "per package" configuration file is absent. The second problem is the question of which format to use and what to name this file. Since file formats and naming has never been controversial at all, this will obviously be the easy part of this problem. But the file should be parsable by both wrap-and-sort and the language server, so you get the same result regardless of which tool you use. If we do not ensure this, then we still have the style ping-pong problem as people use different tools. This also seems like time sink with no end. So, what next then...?
What next? On the language server front, I will have a look at its support for providing semantic hints to the editors that might be used for syntax highlighting. While I think most common Debian editors have built syntax highlighting already, I would like this language server to stand on its own. I would like us to be in a situation where we do not have implement yet another editor extension for Debian packaging files. At least not for editors that support the LSP spec. On a different front, I have an idea for how we go about relationship related substvars. It is not directly related to this language server, except I got triggered by the language server "missing" a diagnostic for reminding people to add the magic Depends: $ misc:Depends [, $ shlibs:Depends ] boilerplate. The magic boilerplate that you have to write even though we really should just fix this at a tooling level instead. Energy permitting, I will formulate a proposal for that and send it to debian-devel. Beyond that, I think I might start adding support for another file. I also need to wrap up my python-debian branch, so I can get the position support into the Debian soon, which would remove one papercut for using this language server. Finally, it might be interesting to see if I can extract a "batch-linter" version of the diagnostics and related quickfix features. If nothing else, the "linter" variant would enable many of you to get a "mini-Lintian" without having to do a package build first.

16 February 2024

David Bremner: Generating ikiwiki markdown from org

My web pages are (still) in ikiwiki, but lately I have started authoring things like assignments and lectures in org-mode so that I can have some literate programming facilities. There is is org-mode export built-in, but it just exports source blocks as examples (i.e. unhighlighted verbatim). I added a custom exporter to mark up source blocks in a way ikiwiki can understand. Luckily this is not too hard the second time.
(with-eval-after-load "ox-md"
  (org-export-define-derived-backend 'ik 'md
    :translate-alist '((src-block . ik-src-block))
    :menu-entry '(?m 1 ((?i "ikiwiki" ik-export-to-ikiwiki)))))
(defun ik-normalize-language  (str)
  (cond
   ((string-equal str "plait") "racket")
   ((string-equal str "smol") "racket")
   (t str)))
(defun ik-src-block (src-block contents info)
  "Transcode a SRC-BLOCK element from Org to beamer
         CONTENTS is nil.  INFO is a plist used as a communication
         channel."
  (let* ((body  (org-element-property :value src-block))
         (lang  (ik-normalize-language (org-element-property :language src-block))))
    (format "[[!format <span class="error">Error: unsupported page format &#37;s</span>]]" lang body)))
(defun ik-export-to-ikiwiki
    (&optional async subtreep visible-only body-only ext-plist)
  "Export current buffer as an ikiwiki markdown file.
    See org-md-export-to-markdown for full docs"
  (require 'ox)
  (interactive)
  (let ((file (org-export-output-file-name ".mdwn" subtreep)))
    (org-export-to-file 'ik file
      async subtreep visible-only body-only ext-plist)))

1 February 2024

Russ Allbery: Review: System Collapse

Review: System Collapse, by Martha Wells
Series: Murderbot Diaries #7
Publisher: Tordotcom
Copyright: 2023
ISBN: 1-250-82698-5
Format: Kindle
Pages: 245
System Collapse is the second Murderbot novel. Including the novellas, it's the 7th in the series. Unlike Fugitive Telemetry, the previous novella that was out of chronological order, this is the direct sequel to Network Effect. A very direct sequel; it picks up just a few days after the previous novel ended. Needless to say, you should not start here. I was warned by other people and therefore re-read Network Effect immediately before reading System Collapse. That was an excellent idea, since this novel opens with a large cast, no dramatis personae, not much in the way of a plot summary, and a lot of emotional continuity from the previous novel. I would grumble about this more, like I have in other reviews, but I thoroughly enjoyed re-reading Network Effect and appreciated the excuse.
ART-drone said, I wouldn t recommend it. I lack a sense of proportional response. I don t advise engaging with me on any level.
Saying much about the plot of this book without spoiling Network Effect and the rest of the series is challenging. Murderbot is suffering from the aftereffects of the events of the previous book more than it expected or would like to admit. It and its humans are in the middle of a complicated multi-way negotiation with some locals, who the corporates are trying to exploit. One of the difficulties in that negotiation is getting people to believe that the corporations are as evil as they actually are, a plot element that has a depressing amount in common with current politics. Meanwhile, Murderbot is trying to keep everyone alive. I loved Network Effect, but that was primarily for the social dynamics. The planet that was central to the novel was less interesting, so another (short) novel about the same planet was a bit of a disappointment. This does give Wells a chance to show in more detail what Murderbot's new allies have been up to, but there is a lot of speculative exploration and detailed descriptions of underground tunnels that I found less compelling than the relationship dynamics of the previous book. (Murderbot, on the other hand, would much prefer exploring creepy abandoned tunnels to talking about its feelings.) One of the things this series continues to do incredibly well, though, is take non-human intelligence seriously in a world where the humans mostly don't. It perfectly fills a gap between Star Wars, where neither the humans nor the story take non-human intelligences seriously (hence the creepy slavery vibes as soon as you start paying attention to droids), and the Culture, where both humans and the story do. The corporates (the bad guys in this series) treat non-human intelligences the way Star Wars treats droids. The good guys treat Murderbot mostly like a strange human, which is better but still wrong, and still don't notice the numerous other machine intelligences. But Wells, as the author, takes all of the non-human characters seriously, which means there are complex and fascinating relationships happening at a level of the story that the human characters are mostly unaware of. I love that Murderbot rarely bothers to explain; if the humans are too blinkered to notice, that's their problem. About halfway into the story, System Collapse hits its stride, not coincidentally at the point where Murderbot befriends some new computers. The rest of the book is great. This was not as good as Network Effect. There is a bit less competence porn at the start, and although that's for good in-story reasons I still missed it. Murderbot's redaction of things it doesn't want to talk about got a bit annoying before it finally resolved. And I was not sufficiently interested in this planet to want to spend two novels on it, at least without another major revelation that didn't come. But it's still a Murderbot novel, which means it has the best first-person narrative voice I've ever read, some great moments, and possibly the most compelling and varied presentation of computer intelligence in science fiction at the moment.
There was no feed ID, but AdaCol2 supplied the name Lucia and when I asked it for more info, the gender signifier bb (which didn t translate) and he/him pronouns. (I asked because the humans would bug me for the information; I was as indifferent to human gender as it was possible to be without being unconscious.)
This is not a series to read out of order, but if you have read this far, you will continue to be entertained. You don't need me to tell you this nearly everyone reviewing science fiction is saying it but this series is great and you should read it. Rating: 8 out of 10

24 January 2024

Louis-Philippe V ronneau: Montreal Subway Foot Traffic Data, 2023 edition

For the fifth year in a row, I've asked Soci t de Transport de Montr al, Montreal's transit agency, for the foot traffic data of Montreal's subway. By clicking on a subway station, you'll be redirected to a graph of the station's foot traffic. Licences

20 January 2024

Gunnar Wolf: Ruffle helps bring back my family history

Probably a trait of my family s origins as migrants from East Europe, probably part of the collective trauma of jews throughout the world or probably because that s just who I turned out to be, I hold in high regard the preservation of memory of my family s photos, movies and such items. And it s a trait shared by many people in my familiar group. Shortly after my grandmother died 24 years ago, my mother did a large, loving work of digitalization and restoration of my grandparent s photos. Sadly, the higher resolution copies of said photos is lost but she took the work of not just scanning the photos, but assembling them in presentations, telling a story, introducing my older relatives, many of them missing 40 or more years before my birth. But said presentations were built using Flash. Right, not my choice of tool, and I told her back in the day but given I wasn t around to do the work in what I d chosen (a standards-abiding format, naturally), and given my graphic design skills are nonexistant Several years ago, when Adobe pulled the plug on the Flash format, we realized they would no longer be accessible. I managed to get the photos out of the preentations, but lost the narration, that is a great part of the work. Three days ago, however, I read a post on https://www.osnews.com that made me jump to action: https://www.osnews.com/story/138350/ruffle-an-open-source-flash-player-emulator/. Ruffle is an open source Flash Player emulator, written in Rust and compiled to WASM. Even though several OSnews readers report it to be buggy to play some Flash games they long for, it worked just fine for a simple slideshow presentator. So I managed to bring it back to life! Yes, I d like to make a better index page, but that will come later I am now happy and proud to share with you:

Acariciando la ausencia: Familia Iszaevich Fajerstein, 1900 2000 (which would be roughly translated as Caressing the absence: Iszaevich Fajerstein family, 1900-2000).

Gunnar Wolf: A deep learning technique for intrusion detection system using a recurrent neural networks based framework

This post is a review for Computing Reviews for A deep learning technique for intrusion detection system using a recurrent neural networks based framework , a article published in Computer Communications
So let s assume you already know and understand that artificial intelligence s main building blocks are perceptrons, that is, mathematical models of neurons. And you know that, while a single perceptron is too limited to get interesting information from, very interesting structures neural networks can be built with them. You also understand that neural networks can be trained with large datasets, and you can get them to become quite efficient and accurate classifiers for data comparable to your dataset. Finally, you are interested in applying this knowledge to defensive network security, particularly in choosing the right recurrent neural network (RNN) framework to create an intrusion detection system (IDS). Are you still with me? Good! This paper might be right for you! The paper builds on a robust and well-written introduction and related work sections to arrive at explaining in detail what characterizes a RNN, the focus of this work, among other configurations also known as neural networks, and why they are particularly suited for machine learning (ML) tasks. RNNs must be trained for each problem domain, and publicly available datasets are commonly used for such tasks. The authors present two labeled datasets representing normal and hostile network data, identified according to different criteria: NSL-KDD and UNSW-NB15. They proceed to show a framework to analyze and compare different RNNs and run them against said datasets, segmented for separate training and validation phases, compare results, and finally select the best available model for the task measuring both training speed as well as classification accuracy. The paper is quite heavy due to both its domain-specific terminology many acronyms are used throughout the text and its use of mathematical notation, both to explain specific properties of each of the RNN types and for explaining the preprocessing carried out for feature normalization and selection. This is partly what led me to start the first paragraph by assuming that we, as readers, already understand a large body of material if we are to fully follow the text. The paper does begin by explaining its core technologies, but quickly ramps up and might get too technical for nonexpert readers. It is undeniably an interesting and valuable read, showing the state of the art in IDS and ML-assisted technologies. It does not detail any specific technology applying its findings, but we will probably find the information conveyed here soon enough in industry publications.

Niels Thykier: Making debputy: Writing declarative parsing logic

In this blog post, I will cover how debputy parses its manifest and the conceptual improvements I did to make parsing of the manifest easier. All instructions to debputy are provided via the debian/debputy.manifest file and said manifest is written in the YAML format. After the YAML parser has read the basic file structure, debputy does another pass over the data to extract the information from the basic structure. As an example, the following YAML file:
manifest-version: "0.1"
installations:
  - install:
      source: foo
      dest-dir: usr/bin
would be transformed by the YAML parser into a structure resembling:
 
  "manifest-version": "0.1",
  "installations": [
      
       "install":  
         "source": "foo",
         "dest-dir": "usr/bin",
        
      
  ]
 
This structure is then what debputy does a pass on to translate this into an even higher level format where the "install" part is translated into an InstallRule. In the original prototype of debputy, I would hand-write functions to extract the data that should be transformed into the internal in-memory high level format. However, it was quite tedious. Especially because I wanted to catch every possible error condition and report "You are missing the required field X at Y" rather than the opaque KeyError: X message that would have been the default. Beyond being tedious, it was also quite error prone. As an example, in debputy/0.1.4 I added support for the install rule and you should allegedly have been able to add a dest-dir: or an as: inside it. Except I crewed up the code and debputy was attempting to look up these keywords from a dict that could never have them. Hand-writing these parsers were so annoying that it demotivated me from making manifest related changes to debputy simply because I did not want to code the parsing logic. When I got this realization, I figured I had to solve this problem better. While reflecting on this, I also considered that I eventually wanted plugins to be able to add vocabulary to the manifest. If the API was "provide a callback to extract the details of whatever the user provided here", then the result would be bad.
  1. Most plugins would probably throw KeyError: X or ValueError style errors for quite a while. Worst case, they would end on my table because the user would have a hard time telling where debputy ends and where the plugins starts. "Best" case, I would teach debputy to say "This poor error message was brought to you by plugin foo. Go complain to them". Either way, it would be a bad user experience.
  2. This even assumes plugin providers would actually bother writing manifest parsing code. If it is that difficult, then just providing a custom file in debian might tempt plugin providers and that would undermine the idea of having the manifest be the sole input for debputy.
So beyond me being unsatisfied with the current situation, it was also clear to me that I needed to come up with a better solution if I wanted externally provided plugins for debputy. To put a bit more perspective on what I expected from the end result:
  1. It had to cover as many parsing errors as possible. An error case this code would handle for you, would be an error where I could ensure it sufficient degree of detail and context for the user.
  2. It should be type-safe / provide typing support such that IDEs/mypy could help you when you work on the parsed result.
  3. It had to support "normalization" of the input, such as
           # User provides
           - install: "foo"
           # Which is normalized into:
           - install:
               source: "foo"
4) It must be simple to tell  debputy  what input you expected.
At this point, I remembered that I had seen a Python (PYPI) package where you could give it a TypedDict and an arbitrary input (Sadly, I do not remember the name). The package would then validate the said input against the TypedDict. If the match was successful, you would get the result back casted as the TypedDict. If the match was unsuccessful, the code would raise an error for you. Conceptually, this seemed to be a good starting point for where I wanted to be. Then I looked a bit on the normalization requirement (point 3). What is really going on here is that you have two "schemas" for the input. One is what the programmer will see (the normalized form) and the other is what the user can input (the manifest form). The problem is providing an automatic normalization from the user input to the simplified programmer structure. To expand a bit on the following example:
# User provides
- install: "foo"
# Which is normalized into:
- install:
    source: "foo"
Given that install has the attributes source, sources, dest-dir, as, into, and when, how exactly would you automatically normalize "foo" (str) into source: "foo"? Even if the code filtered by "type" for these attributes, you would end up with at least source, dest-dir, and as as candidates. Turns out that TypedDict actually got this covered. But the Python package was not going in this direction, so I parked it here and started looking into doing my own. At this point, I had a general idea of what I wanted. When defining an extension to the manifest, the plugin would provide debputy with one or two definitions of TypedDict. The first one would be the "parsed" or "target" format, which would be the normalized form that plugin provider wanted to work on. For this example, lets look at an earlier version of the install-examples rule:
# Example input matching this typed dict.
#    
#       "source": ["foo"]
#       "into": ["pkg"]
#    
class InstallExamplesTargetFormat(TypedDict):
    # Which source files to install (dest-dir is fixed)
    sources: List[str]
    # Which package(s) that should have these files installed.
    into: NotRequired[List[str]]
In this form, the install-examples has two attributes - both are list of strings. On the flip side, what the user can input would look something like this:
# Example input matching this typed dict.
#    
#       "source": "foo"
#       "into": "pkg"
#    
#
class InstallExamplesManifestFormat(TypedDict):
    # Note that sources here is split into source (str) vs. sources (List[str])
    sources: NotRequired[List[str]]
    source: NotRequired[str]
    # We allow the user to write  into: foo  in addition to  into: [foo] 
    into: Union[str, List[str]]
FullInstallExamplesManifestFormat = Union[
    InstallExamplesManifestFormat,
    List[str],
    str,
]
The idea was that the plugin provider would use these two definitions to tell debputy how to parse install-examples. Pseudo-registration code could look something like:
def _handler(
    normalized_form: InstallExamplesTargetFormat,
) -> InstallRule:
    ...  # Do something with the normalized form and return an InstallRule.
concept_debputy_api.add_install_rule(
  keyword="install-examples",
  target_form=InstallExamplesTargetFormat,
  manifest_form=FullInstallExamplesManifestFormat,
  handler=_handler,
)
This was my conceptual target and while the current actual API ended up being slightly different, the core concept remains the same.
From concept to basic implementation Building this code is kind like swallowing an elephant. There was no way I would just sit down and write it from one end to the other. So the first prototype of this did not have all the features it has now. Spoiler warning, these next couple of sections will contain some Python typing details. When reading this, it might be helpful to know things such as Union[str, List[str]] being the Python type for either a str (string) or a List[str] (list of strings). If typing makes your head spin, these sections might less interesting for you. To build this required a lot of playing around with Python's introspection and typing APIs. My very first draft only had one "schema" (the normalized form) and had the following features:
  • Read TypedDict.__required_attributes__ and TypedDict.__optional_attributes__ to determine which attributes where present and which were required. This was used for reporting errors when the input did not match.
  • Read the types of the provided TypedDict, strip the Required / NotRequired markers and use basic isinstance checks based on the resulting type for str and List[str]. Again, used for reporting errors when the input did not match.
This prototype did not take a long (I remember it being within a day) and worked surprisingly well though with some poor error messages here and there. Now came the first challenge, adding the manifest format schema plus relevant normalization rules. The very first normalization I did was transforming into: Union[str, List[str]] into into: List[str]. At that time, source was not a separate attribute. Instead, sources was a Union[str, List[str]], so it was the only normalization I needed for all my use-cases at the time. There are two problems when writing a normalization. First is determining what the "source" type is, what the target type is and how they relate. The second is providing a runtime rule for normalizing from the manifest format into the target format. Keeping it simple, the runtime normalizer for Union[str, List[str]] -> List[str] was written as:
def normalize_into_list(x: Union[str, List[str]]) -> List[str]:
    return x if isinstance(x, list) else [x]
This basic form basically works for all types (assuming none of the types will have List[List[...]]). The logic for determining when this rule is applicable is slightly more involved. My current code is about 100 lines of Python code that would probably lose most of the casual readers. For the interested, you are looking for _union_narrowing in declarative_parser.py With this, when the manifest format had Union[str, List[str]] and the target format had List[str] the generated parser would silently map a string into a list of strings for the plugin provider. But with that in place, I had covered the basics of what I needed to get started. I was quite excited about this milestone of having my first keyword parsed without handwriting the parser logic (at the expense of writing a more generic parse-generator framework).
Adding the first parse hint With the basic implementation done, I looked at what to do next. As mentioned, at the time sources in the manifest format was Union[str, List[str]] and I considered to split into a source: str and a sources: List[str] on the manifest side while keeping the normalized form as sources: List[str]. I ended up committing to this change and that meant I had to solve the problem getting my parser generator to understand the situation:
# Map from
class InstallExamplesManifestFormat(TypedDict):
    # Note that sources here is split into source (str) vs. sources (List[str])
    sources: NotRequired[List[str]]
    source: NotRequired[str]
    # We allow the user to write  into: foo  in addition to  into: [foo] 
    into: Union[str, List[str]]
# ... into
class InstallExamplesTargetFormat(TypedDict):
    # Which source files to install (dest-dir is fixed)
    sources: List[str]
    # Which package(s) that should have these files installed.
    into: NotRequired[List[str]]
There are two related problems to solve here:
  1. How will the parser generator understand that source should be normalized and then mapped into sources?
  2. Once that is solved, the parser generator has to understand that while source and sources are declared as NotRequired, they are part of a exactly one of rule (since sources in the target form is Required). This mainly came down to extra book keeping and an extra layer of validation once the previous step is solved.
While working on all of this type introspection for Python, I had noted the Annotated[X, ...] type. It is basically a fake type that enables you to attach metadata into the type system. A very random example:
# For all intents and purposes,  foo  is a string despite all the  Annotated  stuff.
foo: Annotated[str, "hello world"] = "my string here"
The exciting thing is that you can put arbitrary details into the type field and read it out again in your introspection code. Which meant, I could add "parse hints" into the type. Some "quick" prototyping later (a day or so), I got the following to work:
# Map from
#      
#        "source": "foo"  # (or "sources": ["foo"])
#        "into": "pkg"
#      
class InstallExamplesManifestFormat(TypedDict):
    # Note that sources here is split into source (str) vs. sources (List[str])
    sources: NotRequired[List[str]]
    source: NotRequired[
        Annotated[
            str,
            DebputyParseHint.target_attribute("sources")
        ]
    ]
    # We allow the user to write  into: foo  in addition to  into: [foo] 
    into: Union[str, List[str]]
# ... into
#      
#        "source": ["foo"]
#        "into": ["pkg"]
#      
class InstallExamplesTargetFormat(TypedDict):
    # Which source files to install (dest-dir is fixed)
    sources: List[str]
    # Which package(s) that should have these files installed.
    into: NotRequired[List[str]]
Without me (as a plugin provider) writing a line of code, I can have debputy rename or "merge" attributes from the manifest form into the normalized form. Obviously, this required me (as the debputy maintainer) to write a lot code so other me and future plugin providers did not have to write it.
High level typing At this point, basic normalization between one mapping to another mapping form worked. But one thing irked me with these install rules. The into was a list of strings when the parser handed them over to me. However, I needed to map them to the actual BinaryPackage (for technical reasons). While I felt I was careful with my manual mapping, I knew this was exactly the kind of case where a busy programmer would skip the "is this a known package name" check and some user would typo their package resulting in an opaque KeyError: foo. Side note: "Some user" was me today and I was super glad to see debputy tell me that I had typoed a package name (I would have been more happy if I had remembered to use debputy check-manifest, so I did not have to wait through the upstream part of the build that happened before debhelper passed control to debputy...) I thought adding this feature would be simple enough. It basically needs two things:
  1. Conversion table where the parser generator can tell that BinaryPackage requires an input of str and a callback to map from str to BinaryPackage. (That is probably lie. I think the conversion table came later, but honestly I do remember and I am not digging into the git history for this one)
  2. At runtime, said callback needed access to the list of known packages, so it could resolve the provided string.
It was not super difficult given the existing infrastructure, but it did take some hours of coding and debugging. Additionally, I added a parse hint to support making the into conditional based on whether it was a single binary package. With this done, you could now write something like:
# Map from
class InstallExamplesManifestFormat(TypedDict):
    # Note that sources here is split into source (str) vs. sources (List[str])
    sources: NotRequired[List[str]]
    source: NotRequired[
        Annotated[
            str,
            DebputyParseHint.target_attribute("sources")
        ]
    ]
    # We allow the user to write  into: foo  in addition to  into: [foo] 
    into: Union[BinaryPackage, List[BinaryPackage]]
# ... into
class InstallExamplesTargetFormat(TypedDict):
    # Which source files to install (dest-dir is fixed)
    sources: List[str]
    # Which package(s) that should have these files installed.
    into: NotRequired[
        Annotated[
            List[BinaryPackage],
            DebputyParseHint.required_when_multi_binary()
        ]
    ]
Code-wise, I still had to check for into being absent and providing a default for that case (that is still true in the current codebase - I will hopefully fix that eventually). But I now had less room for mistakes and a standardized error message when you misspell the package name, which was a plus.
The added side-effect - Introspection A lovely side-effect of all the parsing logic being provided to debputy in a declarative form was that the generated parser snippets had fields containing all expected attributes with their types, which attributes were required, etc. This meant that adding an introspection feature where you can ask debputy "What does an install rule look like?" was quite easy. The code base already knew all of this, so the "hard" part was resolving the input the to concrete rule and then rendering it to the user. I added this feature recently along with the ability to provide online documentation for parser rules. I covered that in more details in my blog post Providing online reference documentation for debputy in case you are interested. :)
Wrapping it up This was a short insight into how debputy parses your input. With this declarative technique:
  • The parser engine handles most of the error reporting meaning users get most of the errors in a standard format without the plugin provider having to spend any effort on it. There will be some effort in more complex cases. But the common cases are done for you.
  • It is easy to provide flexibility to users while avoiding having to write code to normalize the user input into a simplified programmer oriented format.
  • The parser handles mapping from basic types into higher forms for you. These days, we have high level types like FileSystemMode (either an octal or a symbolic mode), different kind of file system matches depending on whether globs should be performed, etc. These types includes their own validation and parsing rules that debputy handles for you.
  • Introspection and support for providing online reference documentation. Also, debputy checks that the provided attribute documentation covers all the attributes in the manifest form. If you add a new attribute, debputy will remind you if you forget to document it as well. :)
In this way everybody wins. Yes, writing this parser generator code was more enjoyable than writing the ad-hoc manual parsers it replaced. :)

11 January 2024

Matthias Klumpp: Wayland really breaks things Just for now?

This post is in part a response to an aspect of Nate s post Does Wayland really break everything? , but also my reflection on discussing Wayland protocol additions, a unique pleasure that I have been involved with for the past months1.

Some facts Before I start I want to make a few things clear: The Linux desktop will be moving to Wayland2 this is a fact at this point (and has been for a while), sticking to X11 makes no sense for future projects. From reading Wayland protocols and working with it at a much lower level than I ever wanted to, it is also very clear to me that Wayland is an exceptionally well-designed core protocol, and so are the additional extension protocols (xdg-shell & Co.). The modularity of Wayland is great, it gives it incredible flexibility and will for sure turn out to be good for the long-term viability of this project (and also provides a path to correct protocol issues in future, if one is found). In other words: Wayland is an amazing foundation to build on, and a lot of its design decisions make a lot of sense! The shift towards people seeing Linux more as an application developer platform, and taking PipeWire and XDG Portals into account when designing for Wayland is also an amazing development and I love to see this this holistic approach is something I always wanted! Furthermore, I think Wayland removes a lot of functionality that shouldn t exist in a modern compositor and that s a good thing too! Some of X11 s features and design decisions had clear drawbacks that we shouldn t replicate. I highly recommend to read Nate s blog post, it s very good and goes into more detail. And due to all of this, I firmly believe that any advancement in the Wayland space must come from within the project.

But! But! Of course there was a but coming  I think while developing Wayland-as-an-ecosystem we are now entrenched into narrow concepts of how a desktop should work. While discussing Wayland protocol additions, a lot of concepts clash, people from different desktops with different design philosophies debate the merits of those over and over again never reaching any conclusion (just as you will never get an answer out of humans whether sushi or pizza is the clearly superior food, or whether CSD or SSD is better). Some people want to use Wayland as a vehicle to force applications to submit to their desktop s design philosophies, others prefer the smallest and leanest protocol possible, other developers want the most elegant behavior possible. To be clear, I think those are all very valid approaches. But this also creates problems: By switching to Wayland compositors, we are already forcing a lot of porting work onto toolkit developers and application developers. This is annoying, but just work that has to be done. It becomes frustrating though if Wayland provides toolkits with absolutely no way to reach their goal in any reasonable way. For Nate s Photoshop analogy: Of course Linux does not break Photoshop, it is Adobe s responsibility to port it. But what if Linux was missing a crucial syscall that Photoshop needed for proper functionality and Adobe couldn t port it without that? In that case it becomes much less clear on who is to blame for Photoshop not being available. A lot of Wayland protocol work is focused on the environment and design, while applications and work to port them often is considered less. I think this happens because the overlap between application developers and developers of the desktop environments is not necessarily large, and the overlap with people willing to engage with Wayland upstream is even smaller. The combination of Windows developers porting apps to Linux and having involvement with toolkits or Wayland is pretty much nonexistent. So they have less of a voice.

A quick detour through the neuroscience research lab I have been involved with Freedesktop, GNOME and KDE for an incredibly long time now (more than a decade), but my actual job (besides consulting for Purism) is that of a PhD candidate in a neuroscience research lab (working on the morphology of biological neurons and its relation to behavior). I am mostly involved with three research groups in our institute, which is about 35 people. Most of us do all our data analysis on powerful servers which we connect to using RDP (with KDE Plasma as desktop). Since I joined, I have been pushing the envelope a bit to extend Linux usage to data acquisition and regular clients, and to have our data acquisition hardware interface well with it. Linux brings some unique advantages for use in research, besides the obvious one of having every step of your data management platform introspectable with no black boxes left, a goal I value very highly in research (but this would be its own blogpost). In terms of operating system usage though, most systems are still Windows-based. Windows is what companies develop for, and what people use by default and are familiar with. The choice of operating system is very strongly driven by application availability, and WSL being really good makes this somewhat worse, as it removes the need for people to switch to a real Linux system entirely if there is the occasional software requiring it. Yet, we have a lot more Linux users than before, and use it in many places where it makes sense. I also developed a novel data acquisition software that even runs on Linux-only and uses the abilities of the platform to its fullest extent. All of this resulted in me asking existing software and hardware vendors for Linux support a lot more often. Vendor-customer relationship in science is usually pretty good, and vendors do usually want to help out. Same for open source projects, especially if you offer to do Linux porting work for them But overall, the ease of use and availability of required applications and their usability rules supreme. Most people are not technically knowledgeable and just want to get their research done in the best way possible, getting the best results with the least amount of friction.
KDE/Linux usage at a control station for a particle accelerator at Adlershof Technology Park, Germany, for reference (by 25years of KDE)3

Back to the point The point of that story is this: GNOME, KDE, RHEL, Debian or Ubuntu: They all do not matter if the necessary applications are not available for them. And as soon as they are, the easiest-to-use solution wins. There are many facets of easiest : In many cases this is RHEL due to Red Hat support contracts being available, in many other cases it is Ubuntu due to its mindshare and ease of use. KDE Plasma is also frequently seen, as it is perceived a bit easier to onboard Windows users with it (among other benefits). Ultimately, it comes down to applications and 3rd-party support though. Here s a dirty secret: In many cases, porting an application to Linux is not that difficult. The thing that companies (and FLOSS projects too!) struggle with and will calculate the merits of carefully in advance is whether it is worth the support cost as well as continuous QA/testing. Their staff will have to do all of that work, and they could spend that time on other tasks after all. So if they learn that porting to Linux not only means added testing and support, but also means to choose between the legacy X11 display server that allows for 1:1 porting from Windows or the new Wayland compositors that do not support the same features they need, they will quickly consider it not worth the effort at all. I have seen this happen. Of course many apps use a cross-platform toolkit like Qt, which greatly simplifies porting. But this just moves the issue one layer down, as now the toolkit needs to abstract Windows, macOS and Wayland. And Wayland does not contain features to do certain things or does them very differently from e.g. Windows, so toolkits have no way to actually implement the existing functionality in a way that works on all platforms. So in Qt s documentation you will often find texts like works everywhere except for on Wayland compositors or mobile 4. Many missing bits or altered behavior are just papercuts, but those add up. And if users will have a worse experience, this will translate to more support work, or people not wanting to use the software on the respective platform.

What s missing?

Window positioning SDI applications with multiple windows are very popular in the scientific world. For data acquisition (for example with microscopes) we often have one monitor with control elements and one larger one with the recorded image. There is also other configurations where multiple signal modalities are acquired, and the experimenter aligns windows exactly in the way they want and expects the layout to be stored and to be loaded upon reopening the application. Even in the image from Adlershof Technology Park above you can see this style of UI design, at mega-scale. Being able to pop-out elements as windows from a single-window application to move them around freely is another frequently used paradigm, and immensely useful with these complex apps. It is important to note that this is not a legacy design, but in many cases an intentional choice these kinds of apps work incredibly well on larger screens or many screens and are very flexible (you can have any window configuration you want, and switch between them using the (usually) great window management abilities of your desktop). Of course, these apps will work terribly on tablets and small form factors, but that is not the purpose they were designed for and nobody would use them that way. I assumed for sure these features would be implemented at some point, but when it became clear that that would not happen, I created the ext-placement protocol which had some good discussion but was ultimately rejected from the xdg namespace. I then tried another solution based on feedback, which turned out not to work for most apps, and now proposed xdg-placement (v2) in an attempt to maybe still get some protocol done that we can agree on, exploring more options before pushing the existing protocol for inclusion into the ext Wayland protocol namespace. Meanwhile though, we can not port any application that needs this feature, while at the same time we are switching desktops and distributions to Wayland by default.

Window position restoration Similarly, a protocol to save & restore window positions was already proposed in 2018, 6 years ago now, but it has still not been agreed upon, and may not even help multiwindow apps in its current form. The absence of this protocol means that applications can not restore their former window positions, and the user has to move them to their previous place again and again. Meanwhile, toolkits can not adopt these protocols and applications can not use them and can not be ported to Wayland without introducing papercuts.

Window icons Similarly, individual windows can not set their own icons, and not-installed applications can not have an icon at all because there is no desktop-entry file to load the icon from and no icon in the theme for them. You would think this is a niche issue, but for applications that create many windows, providing icons for them so the user can find them is fairly important. Of course it s not the end of the world if every window has the same icon, but it s one of those papercuts that make the software slightly less user-friendly. Even applications with fewer windows like LibrePCB are affected, so much so that they rather run their app through Xwayland for now. I decided to address this after I was working on data analysis of image data in a Python virtualenv, where my code and the Python libraries used created lots of windows all with the default yellow W icon, making it impossible to distinguish them at a glance. This is xdg-toplevel-icon now, but of course it is an uphill battle where the very premise of needing this is questioned. So applications can not use it yet.

Limited window abilities requiring specialized protocols Firefox has a picture-in-picture feature, allowing it to pop out media from a mediaplayer as separate floating window so the user can watch the media while doing other things. On X11 this is easily realized, but on Wayland the restrictions posed on windows necessitate a different solution. The xdg-pip protocol was proposed for this specialized usecase, but it is also not merged yet. So this feature does not work as well on Wayland.

Automated GUI testing / accessibility / automation Automation of GUI tasks is a powerful feature, so is the ability to auto-test GUIs. This is being worked on, with libei and wlheadless-run (and stuff like ydotool exists too), but we re not fully there yet.

Wayland is frustrating for (some) application authors As you see, there is valid applications and valid usecases that can not be ported yet to Wayland with the same feature range they enjoyed on X11, Windows or macOS. So, from an application author s perspective, Wayland does break things quite significantly, because things that worked before can no longer work and Wayland (the whole stack) does not provide any avenue to achieve the same result. Wayland does break screen sharing, global hotkeys, gaming latency (via no tearing ) etc, however for all of these there are solutions available that application authors can port to. And most developers will gladly do that work, especially since the newer APIs are usually a lot better and more robust. But if you give application authors no path forward except use Xwayland and be on emulation as second-class citizen forever , it just results in very frustrated application developers. For some application developers, switching to a Wayland compositor is like buying a canvas from the Linux shop that forces your brush to only draw triangles. But maybe for your avant-garde art, you need to draw a circle. You can approximate one with triangles, but it will never be as good as the artwork of your friends who got their canvases from the Windows or macOS art supply shop and have more freedom to create their art.

Triangles are proven to be the best shape! If you are drawing circles you are creating bad art! Wayland, via its protocol limitations, forces a certain way to build application UX often for the better, but also sometimes to the detriment of users and applications. The protocols are often fairly opinionated, a result of the lessons learned from X11. In any case though, it is the odd one out Windows and macOS do not pose the same limitations (for better or worse!), and the effort to port to Wayland is orders of magnitude bigger, or sometimes in case of the multiwindow UI paradigm impossible to achieve to the same level of polish. Desktop environments of course have a design philosophy that they want to push, and want applications to integrate as much as possible (same as macOS and Windows!). However, there are many applications out there, and pushing a design via protocol limitations will likely just result in fewer apps.

The porting dilemma I spent probably way too much time looking into how to get applications cross-platform and running on Linux, often talking to vendors (FLOSS and proprietary) as well. Wayland limitations aren t the biggest issue by far, but they do start to come come up now, especially in the scientific space with Ubuntu having switched to Wayland by default. For application authors there is often no way to address these issues. Many scientists do not even understand why their Python script that creates some GUIs suddenly behaves weirdly because Qt is now using the Wayland backend on Ubuntu instead of X11. They do not know the difference and also do not want to deal with these details even though they may be programmers as well, the real goal is not to fiddle with the display server, but to get to a scientific result somehow. Another issue is portability layers like Wine which need to run Windows applications as-is on Wayland. Apparently Wine s Wayland driver has some heuristics to make window positioning work (and I am amazed by the work done on this!), but that can only go so far.

A way out? So, how would we actually solve this? Fundamentally, this excessively long blog post boils down to just one essential question: Do we want to force applications to submit to a UX paradigm unconditionally, potentially loosing out on application ports or keeping apps on X11 eternally, or do we want to throw them some rope to get as many applications ported over to Wayland, even through we might sacrifice some protocol purity? I think we really have to answer that to make the discussions on wayland-protocols a lot less grueling. This question can be answered at the wayland-protocols level, but even more so it must be answered by the individual desktops and compositors. If the answer for your environment turns out to be Yes, we want the Wayland protocol to be more opinionated and will not make any compromises for application portability , then your desktop/compositor should just immediately NACK protocols that add something like this and you simply shouldn t engage in the discussion, as you reject the very premise of the new protocol: That it has any merit to exist and is needed in the first place. In this case contributors to Wayland and application authors also know where you stand, and a lot of debate is skipped. Of course, if application authors want to support your environment, you are basically asking them now to rewrite their UI, which they may or may not do. But at least they know what to expect and how to target your environment. If the answer turns out to be We do want some portability , the next question obviously becomes where the line should be drawn and which changes are acceptable and which aren t. We can t blindly copy all X11 behavior, some porting work to Wayland is simply inevitable. Some written rules for that might be nice, but probably more importantly, if you agree fundamentally that there is an issue to be fixed, please engage in the discussions for the respective MRs! We for sure do not want to repeat X11 mistakes, and I am certain that we can implement protocols which provide the required functionality in a way that is a nice compromise in allowing applications a path forward into the Wayland future, while also being as good as possible and improving upon X11. For example, the toplevel-icon proposal is already a lot better than anything X11 ever had. Relaxing ACK requirements for the ext namespace is also a good proposed administrative change, as it allows some compositors to add features they want to support to the shared repository easier, while also not mandating them for others. In my opinion, it would allow for a lot less friction between the two different ideas of how Wayland protocol development should work. Some compositors could move forward and support more protocol extensions, while more restrictive compositors could support less things. Applications can detect supported protocols at launch and change their behavior accordingly (ideally even abstracted by toolkits). You may now say that a lot of apps are ported, so surely this issue can not be that bad. And yes, what Wayland provides today may be enough for 80-90% of all apps. But what I hope the detour into the research lab has done is convince you that this smaller percentage of apps matters. A lot. And that it may be worthwhile to support them. To end on a positive note: When it came to porting concrete apps over to Wayland, the only real showstoppers so far5 were the missing window-positioning and window-position-restore features. I encountered them when porting my own software, and I got the issue as feedback from colleagues and fellow engineers. In second place was UI testing and automation support, the window-icon issue was mentioned twice, but being a cosmetic issue it likely simply hurts people less and they can ignore it easier. What this means is that the majority of apps are already fine, and many others are very, very close! A Wayland future for everyone is within our grasp!  I will also bring my two protocol MRs to their conclusion for sure, because as application developers we need clarity on what the platform (either all desktops or even just a few) supports and will or will not support in future. And the only way to get something good done is by contribution and friendly discussion.

Footnotes
  1. Apologies for the clickbait-y title it comes with the subject
  2. When I talk about Wayland I mean the combined set of display server protocols and accepted protocol extensions, unless otherwise clarified.
  3. I would have picked a picture from our lab, but that would have needed permission first
  4. Qt has awesome platform issues pages, like for macOS and Linux/X11 which help with porting efforts, but Qt doesn t even list Linux/Wayland as supported platform. There is some information though, like window geometry peculiarities, which aren t particularly helpful when porting (but still essential to know).
  5. Besides issues with Nvidia hardware CUDA for simulations and machine-learning is pretty much everywhere, so Nvidia cards are common, which causes trouble on Wayland still. It is improving though.

10 January 2024

Simon Josefsson: Trisquel on arm64: Ampere Altra

Having had success running Trisquel on the ppc64 Talos II, I felt ready to get an arm64 machine running Trisquel. I have a Ampere Altra Developer Platform from ADLINK, which is a fairly powerful desktop machine. While there were some issues during installation, I m happy to say the machine is stable and everything appears to work fine. ISO images for non-amd64 platforms are unfortunately still hidden from the main Trisquel download area, so you will have to use the following procedure to download and extract a netinst ISO image (using debian-installer) and write it to a USB memory device. Another unfortunate problem is that there are no OpenPGP signatures or hash checksums, but below I publish one checksum.
wget -q http://builds.trisquel.org/debian-installer-images/debian-installer-images_20210731+deb11u9+11.0trisquel15_arm64.tar.gz
tar xfa debian-installer-images_20210731+deb11u9+11.0trisquel15_arm64.tar.gz ./installer-arm64/20210731+deb11u9+11/images/netboot/mini.iso
echo '311732519cc8c7c1bb2fe873f134fdafb211ef3bcb5b0d2ecdc6ea4e3b336357  installer-arm64/20210731+deb11u9+11/images/netboot/mini.iso'   sha256sum -c
sudo wipefs -a /dev/sdX
sudo dd if=installer-arm64/20210731+deb11u9+11/images/netboot/mini.iso of=/dev/sdX conv=sync status=progress
Insert the USB stick in a USB slot in the machine, and power up. Press ESCAPE at the BIOS prompt and select the USB device as the boot device. The first problem that hit me was that translations didn t work, I selected Swedish but the strings were garbled. Rebooting and selecting the default English worked fine. For installation, you need Internet connectivity and I use the RJ45 port closest to VGA/serial which is available as enP5p1s0 in the installer. I wouldn t connect the BMC RJ45 port to anything unless you understand the security implications. During installation you have to create a EFI partition for booting, and I ended up with one 1GB EFI partition, one 512GB ext4 partition for / with discard/noatime options, and a 32GB swap partition. The installer did not know about any Trisquel mirrors, but only had the default archive.trisquel.org, so if you need to use a mirror, take a note of the necessary details. The installation asks me about which kernel to install, and I went with the default linux-generic which results in a 5.15 linux-libre kernel. At the end of installation, unfortunately grub failed with a mysterious error message: Unable to install GRUB in dummy. Executing 'grub-install dummy' failed. On another console there is a better error message: failed to register the EFI boot entry. There are some references to file descriptor issues. Perhaps I partitioned the disk in a bad way, or this is a real bug in the installer for this platform. I continued installation, and it appears the installer was able to write GRUB to the device, but not add the right boot menu. So I was able to finish the installation properly, and then reboot and manually type the following GRUB commands: linux (hd0,gpt2)/boot/vmlinuz initrd (hd0,gpt2)/boot/initrd.img boot. Use the GRUB ls command to find the right device. See images below for more information. Booting and installing GRUB again manually works fine:
root@ampel:~# update-grub
Sourcing file  /etc/default/grub'
Sourcing file  /etc/default/grub.d/background.cfg'
Sourcing file  /etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.15.0-91-generic
Found initrd image: /boot/initrd.img-5.15.0-91-generic
Found linux image: /boot/vmlinuz-5.15.0-58-generic
Found initrd image: /boot/initrd.img-5.15.0-58-generic
Warning: os-prober will not be executed to detect other bootable partitions.
Systems on them will not be added to the GRUB boot configuration.
Check GRUB_DISABLE_OS_PROBER documentation entry.
Adding boot menu entry for UEFI Firmware Settings ...
done
root@ampel:~# 
During installation I tend to avoid selecting any tasksel components, in part because it didn t use a local mirror to gain network speed, and in part because I don t want to generate OpenSSH keys in a possibly outdated environment that is harder to audit and reproducible rebuild than the finally installed system. When I selected the OpenSSH and GNOME tasksel, I get an error, but fortunately using apt get directly is simple.
root@ampel:~# tasksel
Tasksel GNOME failed:
tasksel: apt-get failed (100)
root@ampel:~# apt-get install trisquel-gnome ssh
Graphics in GNOME was slow using the built-in ASPEED AST2500 VGA controller with linux-libre 5.15. There are kernels labeled 64k but I haven t tested them, and I m not sure they would bring any significant advantage. I simply upgraded to a more recent linux-libre 6.2 kernel via the linux-image-generic-hwe-11.0 virtual package. After a reboot, graphics in GNOME is usable.
root@ampel:~# apt-get install linux-image-generic-hwe-11.0
There seems to be some issue with power-saving inside GNOME, since the machine becomes unresponsive after 20 minutes, and I m unable to make it resume via keyboard or power button. Disabling the inactivity power setting in GNOME works fine to resolve this. I will now put this machine to some more heavy use and see how it handles it. I hope to find more suitable arm64-based servers to complement my ppc64el-based servers in the future, as this ADLINK Ampere Altra Developer Platform with liquid-cooling is more of a toy than a serious server for use in a datacentre. Happy Trisquel-on-arm64 Hacking!

27 December 2023

David Bremner: Added a derived backend for org export

See web-stacker for the background. yantar92 on #org-mode pointed out that a derived backend would be a cleaner solution. I had initially thought it was too complicated, but I have to agree the example in the org-mode documentation does pretty much what I need. This new approach has the big advantage that the generation of URLs happens at export time, so it's not possible for the displayed program code and the version encoded in the URL to get out of sync.
;; derived backend to customize src block handling
(defun my-beamer-src-block (src-block contents info)
  "Transcode a SRC-BLOCK element from Org to beamer
         CONTENTS is nil.  INFO is a plist used as a communication
         channel."
  (let ((attr (org-export-read-attribute :attr_latex src-block :stacker)))
    (concat
     (when (or (not attr) (string= attr "both"))
       (org-export-with-backend 'beamer src-block contents info))
     (when attr
       (let* ((body  (org-element-property :value src-block))
              (table '(? ?\n ?: ?/ ?? ?# ?[ ?] ?@ ?! ?$ ?& ??
                         ?( ?) ?* ?+ ?, ?= ?%))
              (slug (org-link-encode body table))
              (simplified (replace-regexp-in-string "[%]20" "+" slug nil 'literal)))
         (format "\n\\stackerlink %s " simplified))))))
(defun my-beamer-export-to-latex
    (&optional async subtreep visible-only body-only ext-plist)
  "Export current buffer as a (my)Beamer presentation (tex).
    See org-beamer-export-to-latex for full docs"
  (interactive)
  (let ((file (org-export-output-file-name ".tex" subtreep)))
    (org-export-to-file 'my-beamer file
      async subtreep visible-only body-only ext-plist)))
(defun my-beamer-export-to-pdf
    (&optional async subtreep visible-only body-only ext-plist)
  "Export current buffer as a (my)Beamer presentation (PDF).
  See org-beamer-export-to-pdf for full docs."
  (interactive)
  (let ((file (org-export-output-file-name ".tex" subtreep)))
    (org-export-to-file 'my-beamer file
      async subtreep visible-only body-only ext-plist
      #'org-latex-compile)))
(with-eval-after-load "ox-beamer"
  (org-export-define-derived-backend 'my-beamer 'beamer
    :translate-alist '((src-block . my-beamer-src-block))
    :menu-entry '(?l 1 ((?m "my beamer .tex" my-beamer-export-to-latex)
                        (?M "my beamer .pdf" my-beamer-export-to-pdf)))))
An example of using this in an org-document would as below. The first source code block generates only a link in the output while the last adds a generated link to the normal highlighted source code.
* Stuff
** Frame
#+attr_latex: :stacker t
#+NAME: last
#+BEGIN_SRC stacker :eval no
  (f)
#+END_SRC
#+name: smol-example
#+BEGIN_SRC stacker :noweb yes
  (defvar x 1)
  (deffun (f)
    (let ([y 2])
      (deffun (h)
        (+ x y))
      (h)))
  <<last>>
#+END_SRC
** Another Frame 
#+ATTR_LATEX: :stacker both
#+begin_src smol :noweb yes
  <<smol-example>>
#+end_src

20 December 2023

Ulrike Uhlig: How volunteer work in F/LOSS exacerbates pre-existing lines of oppression, and what that has to do with low diversity

This is a post I wrote in June 2022, but did not publish back then. After first publishing it in December 2023, a perfectionist insecure part of me unpublished it again. After receiving positive feedback, i slightly amended and republish it now. In this post, I talk about unpaid work in F/LOSS, taking on the example of hackathons, and why, in my opinion, the expectation of volunteer work is hurting diversity. Disclaimer: I don t have all the answers, only some ideas and questions.

Previous findings In 2006, the Flosspols survey searched to explain the role of gender in free/libre/open source software (F/LOSS) communities because an earlier [study] revealed a significant discrepancy in the proportion of men to women. It showed that just about 1.5% of F/LOSS community members were female at that time, compared with 28% in proprietary software (which is also a low number). Their key findings were, to name just a few:
  • that F/LOSS rewards the producing code rather than the producing software. It thereby puts most emphasis on a particular skill set. Other activities such as interface design or documentation are understood as less technical and therefore less prestigious.
  • The reliance on long hours of intensive computing in writing successful code means that men, who in general assume that time outside of waged labour is theirs , are freer to participate than women, who normally still assume a disproportionate amount of domestic responsibilities. Female F/LOSS participants, however, seem to be able to allocate a disproportionate larger share of their leisure time for their F/LOSS activities. This gives an indication that women who are not able to spend as much time on voluntary activities have difficulties to integrate into the community.
We also know from the 2016 Debian survey, published in 2021, that a majority of Debian contributors are employed, rather than being contractors, and rather than being students. Also, 95.5% of respondents to that study were men between the ages of 30 and 49, highly educated, with the largest groups coming from Germany, France, USA, and the UK. The study found that only 20% of the respondents were being paid to work on Debian. Half of these 20% estimate that the amount of work on Debian they are being paid for corresponds to less than 20% of the work they do there. On the other side, there are 14% of those who are being paid for Debian work who declared that 80-100% of the work they do in Debian is remunerated.

So, if a majority of people is not paid, why do they work on F/LOSS? Or: What are the incentives of free software? In 2021, Louis-Philippe V ronneau aka Pollo, who is not only a Debian Developer but also an economist, published his thesis What are the incentive structures of free software (The actual thesis was written in French). One very interesting finding Pollo pointed out is this one:
Indeed, while we have proven that there is a strong and significative correlation between the income and the participation in a free/libre software project, it is not possible for us to pronounce ourselves about the causality of this link.
In the French original text:
En effet, si nous avons prouv qu il existe une corr lation forte et significative entre le salaire et la participation un projet libre, il ne nous est pas possible de nous prononcer sur la causalit de ce lien.
Said differently, it is certain that there is a relationship between income and F/LOSS contribution, but it s unclear whether working on free/libre software ultimately helps finding a well paid job, or if having a well paid job is the cause enabling work on free/libre software. I would like to scratch this question a bit further, mostly relying on my own observations, experiences, and discussions with F/LOSS contributors.

Volunteer work is unpaid work We often hear of hackathons, hack weeks, or hackfests. I ve been at some such events myself, Tails organized one, the IETF regularly organizes hackathons, and last week (June 2022!) I saw an invitation for a hack week with the Torproject. This type of event generally last several days. While the people who organize these events are being paid by the organizations they work for, participants on the other hand are generally joining on a volunteer basis. Who can we expect to show up at this type of event under these circumstances as participants? To answer this question, I collected some ideas:
  • people who have an employer sponsoring their work
  • people who have a funder/grant sponsoring their work
  • people who have a high income and can take time off easily (in that regard, remember the Gender Pay Gap, women often earn less for the same work than men)
  • people who rely on family wealth (living off an inheritance, living on rights payments from a famous grandparent - I m not making these situations up, there are actual people in such financially favorable situations )
  • people who don t need much money because they don t have to pay rent or pay low rent (besides house owners that category includes people who live in squats or have social welfare paying for their rent, people who live with parents or caretakers)
  • people who don t need to do care work (for children, elderly family members, pets. Remember that most care work is still done by women.)
  • students who have financial support or are in a situation in which they do not yet need to generate a lot of income
  • people who otherwise have free time at their disposal
So, who, in your opinion, fits these unwritten requirements? Looking at this list, it s pretty clear to me why we d mostly find white men from the Global North, generally with higher education in hackathons and F/LOSS development. ( Great, they re a culture fit! ) Yes, there will also always be some people of marginalized groups who will attend such events because they expect to network, to find an internship, to find a better job in the future, or to add their participation to their curriculum. To me, this rings a bunch of alarm bells.

Low diversity in F/LOSS projects a mirror of the distribution of wealth I believe that the lack of diversity in F/LOSS is first of all a mirror of the distribution of wealth on a larger level. And by wealth I m referring to financial wealth as much as to social wealth in the sense of Bourdieu: Families of highly educated parents socially reproducing privilege by allowing their kids to attend better schools, supporting and guiding them in their choices of study and work, providing them with relations to internships acting as springboards into well paid jobs and so on. That said, we should ask ourselves as well:

Do F/LOSS projects exacerbate existing lines of oppression by relying on unpaid work? Let s look again at the causality question of Pollo s research (in my words):
It is unclear whether working on free/libre software ultimately helps finding a well paid job, or if having a well paid job is the cause enabling work on free/libre software.
Maybe we need to imagine this cause-effect relationship over time: as a student, without children and lots of free time, hopefully some money from the state or the family, people can spend time on F/LOSS, collect experience, earn recognition - and later find a well-paid job and make unpaid F/LOSS contributions into a hobby, cementing their status in the community, while at the same time generating a sense of well-being from working on the common good. This is a quite common scenario. As the Flosspols study revealed however, boys often get their own computer at the age of 14, while girls get one only at the age of 20. (These numbers might be slightly different now, and possibly many people don t own an actual laptop or desktop computer anymore, instead they own mobile devices which are not exactly inciting them to look behind the surface, take apart, learn, appropriate technology.) In any case, the above scenario does not allow for people who join F/LOSS later in life, eg. changing careers, to find their place. I believe that F/LOSS projects cannot expect to have more women, people of color, people from working class backgrounds, people from outside of Germany, France, USA, UK, Australia, and Canada on board as long as volunteer work is the status quo and waged labour an earned privilege.

Wait, are you criticizing all these wonderful people who sacrifice their free time to work towards common good? No, that s definitely not my intention, I m glad that F/LOSS exists, and the F/LOSS ecosystem has always represented a small utopia to me that is worth cherishing and nurturing. However, I think we still need to talk more about the lack of diversity, and investigate it further.

Some types of work are never being paid Besides free work at hacking events, let me also underline that a lot of work in F/LOSS is not considered payable work (yes, that s an oxymoron!). Which F/LOSS project for example, has ever paid translators a decent fee? Which project has ever considered that doing the social glue work, often done by women in the projects, is work that should be paid for? Which F/LOSS projects pay the people who do their Debian packaging rather than relying on yet another already well-paid white man who can afford doing this work for free all the while holding up how great the F/LOSS ecosystem is? And how many people on opensourcedesign jobs are looking to get their logo or website done for free? (Isn t that heart icon appealing to your altruistic empathy?) In my experience even F/LOSS projects which are trying to do the right thing by paying everyone the same amount of money per hour run into issues when it turns out that not all hours are equal and that some types of work do not qualify for remuneration at all or that the rules for the clocking of work are not universally applied in the same way by everyone.

Not every interaction should have a monetary value, but Some of you want to keep working without being paid, because that feels a bit like communism within capitalism, it makes you feel good to contribute to the greater good while not having the system determine your value over money. I hear you. I ve been there (and sometimes still am). But as long as we live in this system, even though we didn t choose to and maybe even despise it - communism is not about working for free, it s about getting paid equally and adequately. We may not think about it while under the age of 40 or 45, but working without adequate financial compensation, even half of the time, will ultimately result in not being able to care for oneself when sick, when old. And while this may not be an issue for people who inherit wealth, or have an otherwise safe economical background, eg. an academic salary, it is a huge problem and barrier for many people coming out of the working or service classes. (Oh and please, don t repeat the neoliberal lie that everyone can achieve whatever they aim for, if they just tried hard enough. French research shows that (in France) one has only 30% chance to become a class defector , and change social class upwards. But I managed to get out and move up, so everyone can! - well, if you believe that I m afraid you might be experiencing survivor bias.)

Not all bodies are equally able We should also be aware that not all of us can work with the same amount of energy either. There is yet another category of people who are excluded by the expectation of volunteer work, either because the waged labour they do already eats all of their energy, or because their bodies are not disposed to do that much work, for example because of mental health issues - such as depression-, or because of physical disabilities.

When organizing events relying on volunteer work please think about these things. Yes, you can tell people that they should ask their employer to pay them for attending a hackathon - but, as I ve hopefully shown, that would not do it for many people, especially newcomers. Instead, you could propose a fund to make it possible that people who would not normally attend can attend. DebConf is a good example for having done this for many years.

Conclusively I would like to urge free software projects that have a budget and directly pay some people from it to map where they rely on volunteer work and how this hurts diversity in their project. How do you or your project exacerbate pre-existing lines of oppression by granting or not granting monetary value to certain types of work? What is it that you take for granted? As always, I m curious about your feedback!

Worth a read These ideas are far from being new. Ashe Dryden s well-researched post The ethics of unpaid labor and the OSS community dates back to 2013 and is as important as it was ten years ago.

7 December 2023

Daniel Kahn Gillmor: New OpenPGP certificate for dkg, December 2023

dkg's New OpenPGP certificate in December 2023 In December of 2023, I'm moving to a new OpenPGP certificate. You might know my old OpenPGP certificate, which had an fingerprint of C29F8A0C01F35E34D816AA5CE092EB3A5CA10DBA. My new OpenPGP certificate has a fingerprint of: D477040C70C2156A5C298549BB7E9101495E6BF7. Both certificates have the same set of User IDs:
  • Daniel Kahn Gillmor
  • <dkg@debian.org>
  • <dkg@fifthhorseman.net>
You can find a version of this transition statement signed by both the old and new certificates at: https://dkg.fifthhorseman.net/2023-dkg-openpgp-transition.txt The new OpenPGP certificate is:
-----BEGIN PGP PUBLIC KEY BLOCK-----
xjMEZXEJyxYJKwYBBAHaRw8BAQdA5BpbW0bpl5qCng/RiqwhQINrplDMSS5JsO/Y
O+5Zi7HCwAsEHxYKAH0FgmVxCcsDCwkHCRC7fpEBSV5r90cUAAAAAAAeACBzYWx0
QG5vdGF0aW9ucy5zZXF1b2lhLXBncC5vcmfUAgfN9tyTSxpxhmHA1r63GiI4v6NQ
mrrWVLOBRJYuhQMVCggCmwECHgEWIQTUdwQMcMIValwphUm7fpEBSV5r9wAAmaEA
/3MvYJMxQdLhIG4UDNMVd2bsovwdcTrReJhLYyFulBrwAQD/j/RS+AXQIVtkcO9b
l6zZTAO9x6yfkOZbv0g3eNyrAs0QPGRrZ0BkZWJpYW4ub3JnPsLACwQTFgoAfQWC
ZXEJywMLCQcJELt+kQFJXmv3RxQAAAAAAB4AIHNhbHRAbm90YXRpb25zLnNlcXVv
aWEtcGdwLm9yZ4l+Z3i19Uwjw3CfTNFCDjRsoufMoPOM7vM8HoOEdn/vAxUKCAKb
AQIeARYhBNR3BAxwwhVqXCmFSbt+kQFJXmv3AAALZQEAhJsgouepQVV98BHUH6Sv
WvcKrb8dQEZOvHFbZQQPNWgA/A/DHkjYKnUkCg8Zc+FonqOS/35sHhNA8CwqSQFr
tN4KzRc8ZGtnQGZpZnRoaG9yc2VtYW4ubmV0PsLACgQTFgoAfQWCZXEJywMLCQcJ
ELt+kQFJXmv3RxQAAAAAAB4AIHNhbHRAbm90YXRpb25zLnNlcXVvaWEtcGdwLm9y
ZxLvwkgnslsAuo+IoSa9rv8+nXpbBdab2Ft7n4H9S+d/AxUKCAKbAQIeARYhBNR3
BAxwwhVqXCmFSbt+kQFJXmv3AAAtFgD4wqcUfQl7nGLQOcAEHhx8V0Bg8v9ov8Gs
Y1ei1BEFwAD/cxmxmDSO0/tA+x4pd5yIvzgfGYHSTxKS0Ww3hzjuZA7NE0Rhbmll
bCBLYWhuIEdpbGxtb3LCwA4EExYKAIAFgmVxCcsDCwkHCRC7fpEBSV5r90cUAAAA
AAAeACBzYWx0QG5vdGF0aW9ucy5zZXF1b2lhLXBncC5vcmd7X4TgiINwnzh4jar0
Pf/b5hgxFPngCFxJSmtr/f0YiQMVCggCmQECmwECHgEWIQTUdwQMcMIValwphUm7
fpEBSV5r9wAAMuwBAPtMonKbhGOhOy+8miAb/knJ1cIPBjLupJbjM+NUE1WyAQD1
nyGW+XwwMrprMwc320mdJH9B0jdokJZBiN7++0NoBM4zBGVxCcsWCSsGAQQB2kcP
AQEHQI19uRatkPSFBXh8usgciEDwZxTnnRZYrhIgiFMybBDQwsC/BBgWCgExBYJl
cQnLCRC7fpEBSV5r90cUAAAAAAAeACBzYWx0QG5vdGF0aW9ucy5zZXF1b2lhLXBn
cC5vcmfCopazDnq6hZUsgVyztl5wmDCmxI169YLNu+IpDzJEtQKbAr6gBBkWCgBv
BYJlcQnLCRB3LRYeNc1LgUcUAAAAAAAeACBzYWx0QG5vdGF0aW9ucy5zZXF1b2lh
LXBncC5vcmcQglI7G7DbL9QmaDkzcEuk3QliM4NmleIRUW7VvIBHMxYhBHS8BMQ9
hghL6GcsBnctFh41zUuBAACwfwEAqDULksr8PulKRcIP6N9NI/4KoznyIcuOHi8q
Gk4qxMkBAIeV20SPEnWSw9MWAb0eKEcfupzr/C+8vDvsRMynCWsDFiEE1HcEDHDC
FWpcKYVJu36RAUlea/cAAFD1AP0YsE3Eeig1tkWaeyrvvMf5Kl1tt2LekTNWDnB+
FUG9SgD+Ka8vfPR8wuV8D3y5Y9Qq9xGO+QkEBCW0U1qNypg65QHOOARlcQnLEgor
BgEEAZdVAQUBAQdAWTLEa0WmnhUmDBdWXX0ZlYAa4g1CK/fXg0NPOQSteA4DAQgH
wsAABBgWCgByBYJlcQnLCRC7fpEBSV5r90cUAAAAAAAeACBzYWx0QG5vdGF0aW9u
cy5zZXF1b2lhLXBncC5vcmexrMBZe0QdQ+ZJOZxFkAiwCw2I7yTSF2Ox9GVFWKmA
mAKbDBYhBNR3BAxwwhVqXCmFSbt+kQFJXmv3AABcJQD/f4ltpSvLBOBEh/C2dIYa
dgSuqkCqq0B4WOhFRkWJZlcA/AxqLWG4o8UrrmwrmM42FhgxKtEXwCSHE00u8wR4
Up8G
=9Yc8
-----END PGP PUBLIC KEY BLOCK-----
When I have some reasonable number of certifications, i'll update the certificate associated with my e-mail addresses on https://keys.openpgp.org, in DANE, and in WKD. Until then, those lookups should continue to provide the old certificate.

6 December 2023

Reproducible Builds: Reproducible Builds in November 2023

Welcome to the November 2023 report from the Reproducible Builds project! In these reports we outline the most important things that we have been up to over the past month. As a rather rapid recap, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries (more).

Reproducible Builds Summit 2023 Between October 31st and November 2nd, we held our seventh Reproducible Builds Summit in Hamburg, Germany! Amazingly, the agenda and all notes from all sessions are all online many thanks to everyone who wrote notes from the sessions. As a followup on one idea, started at the summit, Alexander Couzens and Holger Levsen started work on a cache (or tailored front-end) for the snapshot.debian.org service. The general idea is that, when rebuilding Debian, you do not actually need the whole ~140TB of data from snapshot.debian.org; rather, only a very small subset of the packages are ever used for for building. It turns out, for amd64, arm64, armhf, i386, ppc64el, riscv64 and s390 for Debian trixie, unstable and experimental, this is only around 500GB ie. less than 1%. Although the new service not yet ready for usage, it has already provided a promising outlook in this regard. More information is available on https://rebuilder-snapshot.debian.net and we hope that this service becomes usable in the coming weeks. The adjacent picture shows a sticky note authored by Jan-Benedict Glaw at the summit in Hamburg, confirming Holger Levsen s theory that rebuilding all Debian packages needs a very small subset of packages, the text states that 69,200 packages (in Debian sid) list 24,850 packages in their .buildinfo files, in 8,0200 variations. This little piece of paper was the beginning of rebuilder-snapshot and is a direct outcome of the summit! The Reproducible Builds team would like to thank our event sponsors who include Mullvad VPN, openSUSE, Debian, Software Freedom Conservancy, Allotropia and Aspiration Tech.

Beyond Trusting FOSS presentation at SeaGL On November 4th, Vagrant Cascadian presented Beyond Trusting FOSS at SeaGL in Seattle, WA in the United States. Founded in 2013, SeaGL is a free, grassroots technical summit dedicated to spreading awareness and knowledge about free source software, hardware and culture. The summary of Vagrant s talk mentions that it will:
[ ] introduce the concepts of Reproducible Builds, including best practices for developing and releasing software, the tools available to help diagnose issues, and touch on progress towards solving decades-old deeply pervasive fundamental security issues Learn how to verify and demonstrate trust, rather than simply hoping everything is OK!
Germane to the contents of the talk, the slides for Vagrant s talk can be built reproducibly, resulting in a PDF with a SHA1 of cfde2f8a0b7e6ec9b85377eeac0661d728b70f34 when built on Debian bookworm and c21fab273232c550ce822c4b0d9988e6c49aa2c3 on Debian sid at the time of writing.

Human Factors in Software Supply Chain Security Marcel Fourn , Dominik Wermke, Sascha Fahl and Yasemin Acar have published an article in a Special Issue of the IEEE s Security & Privacy magazine. Entitled A Viewpoint on Human Factors in Software Supply Chain Security: A Research Agenda, the paper justifies the need for reproducible builds to reach developers and end-users specifically, and furthermore points out some under-researched topics that we have seen mentioned in interviews. An author pre-print of the article is available in PDF form.

Community updates On our mailing list this month:

openSUSE updates Bernhard M. Wiedemann has created a wiki page outlining an proposal to create a general-purpose Linux distribution which consists of 100% bit-reproducible packages albeit minus the embedded signature within RPM files. It would be based on openSUSE Tumbleweed or, if available, its Slowroll-variant. In addition, Bernhard posted another monthly update for his work elsewhere in openSUSE.

Ubuntu Launchpad now supports .buildinfo files Back in 2017, Steve Langasek filed a bug against Ubuntu s Launchpad code hosting platform to report that .changes files (artifacts of building Ubuntu and Debian packages) reference .buildinfo files that aren t actually exposed by Launchpad itself. This was causing issues when attempting to process .changes files with tools such as Lintian. However, it was noticed last month that, in early August of this year, Simon Quigley had resolved this issue, and .buildinfo files are now available from the Launchpad system.

PHP reproducibility updates There have been two updates from the PHP programming language this month. Firstly, the widely-deployed PHPUnit framework for the PHP programming language have recently released version 10.5.0, which introduces the inclusion of a composer.lock file, ensuring total reproducibility of the shipped binary file. Further details and the discussion that went into their particular implementation can be found on the associated GitHub pull request. In addition, the presentation Leveraging Nix in the PHP ecosystem has been given in late October at the PHP International Conference in Munich by Pol Dellaiera. While the video replay is not yet available, the (reproducible) presentation slides and speaker notes are available.

diffoscope changes diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues. This month, Chris Lamb made a number of changes, including:
  • Improving DOS/MBR extraction by adding support for 7z. [ ]
  • Adding a missing RequiredToolNotFound import. [ ]
  • As a UI/UX improvement, try and avoid printing an extended traceback if diffoscope runs out of memory. [ ]
  • Mark diffoscope as stable on PyPI.org. [ ]
  • Uploading version 252 to Debian unstable. [ ]

Website updates A huge number of notes were added to our website that were taken at our recent Reproducible Builds Summit held between October 31st and November 2nd in Hamburg, Germany. In particular, a big thanks to Arnout Engelen, Bernhard M. Wiedemann, Daan De Meyer, Evangelos Ribeiro Tzaras, Holger Levsen and Orhun Parmaks z. In addition to this, a number of other changes were made, including:

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including:

Reproducibility testing framework The Reproducible Builds project operates a comprehensive testing framework (available at tests.reproducible-builds.org) in order to check packages and other artifacts for reproducibility. In October, a number of changes were made by Holger Levsen:
  • Debian-related changes:
    • Track packages marked as Priority: important in a new package set. [ ][ ]
    • Stop scheduling packages that fail to build from source in bookworm [ ] and bullseye. [ ].
    • Add old releases dashboard link in web navigation. [ ]
    • Permit re-run of the pool_buildinfos script to be re-run for a specific year. [ ]
    • Grant jbglaw access to the osuosl4 node [ ][ ] along with lynxis [ ].
    • Increase RAM on the amd64 Ionos builders from 48 GiB to 64 GiB; thanks IONOS! [ ]
    • Move buster to archived suites. [ ][ ]
    • Reduce the number of arm64 architecture workers from 24 to 16 in order to improve stability [ ], reduce the workers for amd64 from 32 to 28 and, for i386, reduce from 12 down to 8 [ ].
    • Show the entire build history of each Debian package. [ ]
    • Stop scheduling already tested package/version combinations in Debian bookworm. [ ]
  • Snapshot service for rebuilders
    • Add an HTTP-based API endpoint. [ ][ ]
    • Add a Gunicorn instance to serve the HTTP API. [ ]
    • Add an NGINX config [ ][ ][ ][ ]
  • System-health:
    • Detect failures due to HTTP 503 Service Unavailable errors. [ ]
    • Detect failures to update package sets. [ ]
    • Detect unmet dependencies. (This usually occurs with builds of Debian live-build.) [ ]
  • Misc-related changes:
    • do install systemd-ommd on jenkins. [ ]
    • fix harmless typo in squid.conf for codethink04. [ ]
    • fixup: reproducible Debian: add gunicorn service to serve /api for rebuilder-snapshot.d.o. [ ]
    • Increase codethink04 s Squid cache_dir size setting to 16 GiB. [ ]
    • Don t install systemd-oomd as it unfortunately kills sshd [ ]
    • Use debootstrap from backports when commisioning nodes. [ ]
    • Add the live_build_debian_stretch_gnome, debsums-tests_buster and debsums-tests_buster jobs to the zombie list. [ ][ ]
    • Run jekyll build with the --watch argument when building the Reproducible Builds website. [ ]
    • Misc node maintenance. [ ][ ][ ]
Other changes were made as well, however, including Mattia Rizzolo fixing rc.local s Bash syntax so it can actually run [ ], commenting away some file cleanup code that is (potentially) deleting too much [ ] and fixing the html_brekages page for Debian package builds [ ]. Finally, diagnosed and submitted a patch to add a AddEncoding gzip .gz line to the tests.reproducible-builds.org Apache configuration so that Gzip files aren t re-compressed as Gzip which some clients can t deal with (as well as being a waste of time). [ ]

If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

4 December 2023

Russ Allbery: Cumulative haul

I haven't done one of these in quite a while, long enough that I've already read and reviewed many of these books. John Joseph Adams (ed.) The Far Reaches (sff anthology)
Poul Anderson The Shield of Time (sff)
Catherine Asaro The Phoenix Code (sff)
Catherine Asaro The Veiled Web (sff)
Travis Baldree Bookshops & Bonedust (sff)
Sue Burke Semiosis (sff)
Jacqueline Carey Cassiel's Servant (sff)
Rob Copeland The Fund (nonfiction)
Mar Delaney Wolf Country (sff)
J.S. Dewes The Last Watch (sff)
J.S. Dewes The Exiled Fleet (sff)
Mike Duncan Hero of Two Worlds (nonfiction)
Mike Duncan The Storm Before the Storm (nonfiction)
Kate Elliott King's Dragon (sff)
Zeke Faux Number Go Up (nonfiction)
Nicola Griffith Menewood (sff)
S.L. Huang The Water Outlaws (sff)
Alaya Dawn Johnson The Library of Broken Worlds (sff)
T. Kingfisher Thornhedge (sff)
Naomi Kritzer Liberty's Daughter (sff)
Ann Leckie Translation State (sff)
Michael Lewis Going Infinite (nonfiction)
Jenna Moran Magical Bears in the Context of Contemporary Political Theory (sff collection)
Ari North Love and Gravity (graphic novel)
Ciel Pierlot Bluebird (sff)
Terry Pratchett A Hat Full of Sky (sff)
Terry Pratchett Going Postal (sff)
Terry Pratchett Thud! (sff)
Terry Pratchett Wintersmith (sff)
Terry Pratchett Making Money (sff)
Terry Pratchett Unseen Academicals (sff)
Terry Pratchett I Shall Wear Midnight (sff)
Terry Pratchett Snuff (sff)
Terry Pratchett Raising Steam (sff)
Terry Pratchett The Shepherd's Crown (sff)
Aaron A. Reed 50 Years of Text Games (nonfiction)
Dashka Slater Accountable (nonfiction)
Rory Stewart The Marches (nonfiction)
Emily Tesh Silver in the Wood (sff)
Emily Tesh Drowned Country (sff)
Valerie Vales Chilling Effect (sff)
Martha Wells System Collapse (sff)
Martha Wells Witch King (sff)

29 November 2023

Jonathan Dowland: Useful vim plugins: AnsiEsc

Sometimes I have to pore over long debugging logs which have originally been written out to a terminal and marked up with colour or formatting via ANSI escape codes. The formatting definitely makes reading them easier, but I want to read them in Vim, rather than a terminal, and (out of the box) Vim doesn't render the formatting. Cue AnsiEsc.vim: an OG Vim script1 that translates some ANSI escape codes in particular some colour specifying ones into Vim syntax highlighting. This makes viewing and navigating around multi-MiB console log files much nicer.

  1. AnsiEsc is old enough to have been distributed as a script, and then as a "vimball", an invention of the same author to make installing Vim scripts easier. It pre-dates the current fashion for plugins, but someone else has updated it and repackaged it as a plugin. I haven't tried that out.

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