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.

$ sudo apt update
$ sudo apt install flatpak

$ flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

$ which -s gnome-software  && sudo apt install gnome-software-plugin-flatpak
$ which -s plasma-discover && sudo apt install plasma-discover-backend-flatpak

$ dpkg -l   grep xdg-desktop-portal   awk ' print $2 '
xdg-desktop-portal
xdg-desktop-portal-gnome
xdg-desktop-portal-gtk

Flatpak commands are run system-wide by default. If you are installing applications for day-to-day usage, it is recommended to stick with this default behavior.

$ flatpak install flathub org.mozilla.firefox

$ flatpak run org.mozilla.firefox

• from ~/.mozilla/ -- where the Firefox Debian package stores its data
• into ~/.var/app/org.mozilla.firefox/.mozilla/ -- where the Firefox Flatpak app stores its data

# BEWARE! Below I'm erasing data!
$ rm -fr ~/.var/app/org.mozilla.firefox/.mozilla/firefox/
$ cp -a ~/.mozilla/firefox/ ~/.var/app/org.mozilla.firefox/.mozilla/

$ mv ~/.mozilla/firefox ~/.mozilla/firefox.old.$(date --iso-8601=date)

$ cat /usr/local/bin/firefox 
#!/bin/sh
exec flatpak run org.mozilla.firefox "$@"

$ sudo apt update
$ sudo apt full-upgrade

flatpak update [OPTION...] [REF...] Updates applications and runtimes. [...] If no REF is given, everything is updated, as well as appstream info for all remotes.

$ flatpak update

1. Teach myself to run flatpak update additionally to apt update, manually, everytime I update my system.
2. Go crazy: let something automatically update my Flatpak apps, in my back and without my consent.

Adulthood is saying, 'But after this week things will slow down a bit' over and over until you die.

• https://www.debian.org/vote/2021/vote_003
• https://www.debian.org/vote/2022/vote_001

• Python team:
  • I updated zope.testrunner to 6.4.
  • I fixed a build failure in celery-haystack-ng, which included an upstream change to stop using d2to1.
  • I backported an upstream change to fix a build failure in python-json-log-formatter.
  • I updated python-typing-extensions to 4.10.0 to fix a build failure.
  • I updated wcwidth to 0.2.13 to fix a build failure, which included rewriting the Debian patches to update-tables.
  • I updated jsonpickle to 3.0.3 to fix a build failure. As part of this I also needed to fix its tests for new timezone name policies.
• man-db:
  • I updated man(1) with updated information about groff.
  • I documented italic support in man(1).
  • I started on a 2.12.1 release (currently waiting for translations).
• openssh:
  • I added an sshd@.service template to help newer versions of systemd make containers and VMs SSH-accessible over AF_VSOCK sockets.
  • I upgraded openssh to 9.7p1. As part of this I noticed a small bug in the PuTTY version detection in its regression tests.
  • I helped with the 64-bit time_t transition by applying a patch from Simon McVittie to temporarily disable ssh-askpass-gnome on the affected architectures.
  • I re-enabled interoperability tests with Twisted Conch.
  • Following the xz-utils backdoor, I spent some time testing OpenSSH upstream s proposed inline systemd notification patch and suggested a small adjustment.
• debconf:
  • I fixed dpkg-preconfigure to not produce errors when run from a non-existing directory.
• parted:
  • I applied a patch from Helmut Grohne to move files to /usr.
• I fixed an off-by-one error in neovim.
• I fixed a number of -Werror=implicit-function-declaration failures (db1-compat, kali, knews, openssh-ssh1, trn4, vigor).
• I fixed a build failure in libsdl-perl, including a reference-counting fix contributed upstream.
• I suggested an rrsync change to make it easier to use it with rsbackup.

• Don t do the obvious thing; it s never what you want
  • Q. Download and run whatever code from the internet?
• Option 1: WTF, no I don t want curl bash
• Option 2: Biting the curl bash bullet
  • Privilege separation
• OMG what a mess

[source.debian-packages]
directory = "/usr/share/cargo/registry"
[source.crates-io]
replace-with = "debian-packages"

/usr-move, by Helmut Grohne Much of the work was spent on handling interaction with time time64 transition and sending patches for mitigating fallout. The set of packages relevant to debootstrap is mostly converted and the patches for glibc and base-files have been refined due to feedback from the upload to Ubuntu noble. Beyond this, he sent patches for all remaining packages that cannot move their files with dh-sequence-movetousr and packages using dpkg-divert in ways that dumat would not recognize.

Upcoming improvements to Salsa CI, by Santiago Ruano Rinc n Last month, Santiago Ruano Rinc n started the work on integrating sbuild into the Salsa CI pipeline. Initially, Santiago used sbuild with the unshare chroot mode. However, after discussion with josch, jochensp and helmut (thanks to them!), it turns out that the unshare mode is not the most suitable for the pipeline, since the level of isolation it provides is not needed, and some test suites would fail (eg: krb5). Additionally, one of the requirements of the build job is the use of ccache, since it is needed by some C/C++ large projects to reduce the compilation time. In the preliminary work with unshare last month, it was not possible to make ccache to work. Finally, Santiago changed the chroot mode, and now has a couple of POC (cf: 1 and 2) that rely on the schroot and sudo, respectively. And the good news is that ccache is successfully used by sbuild with schroot! The image here comes from an example of building grep. At the end of the build, ccache -s shows the statistics of the cache that it used, and so a little more than half of the calls of that job were cacheable. The most important pieces are in place to finish the integration of sbuild into the pipeline. Other than that, Santiago also reviewed the very useful merge request !346, made by IOhannes zm lnig to autodetect the release from debian/changelog. As agreed with IOhannes, Santiago is preparing a merge request to include the release autodetection use case in the very own Salsa CI s CI.

Packaging simplemonitor, by Carles Pina i Estany Carles started using simplemonitor in 2017, opened a WNPP bug in 2022 and started packaging simplemonitor dependencies in October 2023. After packaging five direct and indirect dependencies, Carles finally uploaded simplemonitor to unstable in February. During the packaging of simplemonitor, Carles reported a few issues to upstream. Some of these were to make the simplemonitor package build and run tests reproducibly. A reproducibility issue was reprotest overriding the timezone, which broke simplemonitor s tests. There have been discussions on resolving this upstream in simplemonitor and in reprotest, too. Carles also started upgrading or improving some of simplemonitor s dependencies.

Miscellaneous contributions

• Stefano Rivera spent some time doing admin on debian.social infrastructure. Including dealing with a spike of abuse on the Jitsi server.
• Stefano started to prepare a new release of dh-python, including cleaning out a lot of old Python 2.x related code. Thanks to Niels Thykier (outside Freexian) for spear-heading this work.
• DebConf 24 planning is beginning. Stefano discussed venues and finances with the local team and remotely supported a site-visit by Nattie (outside Freexian).
• Also in the DebConf 24 context, Santiago took part in discussions and preparations related to the Content Team.
• A JIT bug was reported against pypy3 in Debian Bookworm. Stefano bisected the upstream history to find the patch (it was already resolved upstream) and released an update to pypy3 in bookworm.
• Enrico participated in /usr-merge discussions with Helmut.
• Colin Watson backported a python-channels-redis fix to bookworm, rediscovered while working on debusine.
• Colin dug into a cluster of celery build failures and tracked the hardest bit down to a Python 3.12 regression, now fixed in unstable. celery should be back in testing once the 64-bit time_t migration is out of the way.
• Thorsten Alteholz uploaded a new upstream version of cpdb-libs. Unfortunately upstream changed the naming of their release tags, so updating the watch file was a bit demanding. Anyway this version 2.0 is a huge step towards introduction of the new Common Print Dialog Backends.
• Helmut send patches for 48 cross build failures.
• Helmut changed debvm to use mkfs.ext4 instead of genext2fs.
• Helmut sent a debci MR for improving collector robustness.
• In preparation for DebConf 25, Santiago worked on the Brest Bid.

How to Fix it Yourself If what you, like me, need is simply for Bluetooth Audio to work with AAC in Debian s default desktop environment², then you ll need to rebuild the pipewire package to include the AAC codec. While the current version in Debian main has been built with AAC deliberately disabled, it is trivial to enable if you can install a version of the fdk-aac library. I preface this with the usual caveats when it comes to patent and licensing controversies. I am not a lawyer, building this package and/or using it could get you into legal trouble. These instructions have only been tested on an up-to-date copy of Debian 12.

1. Install pipewire s build dependencies

   sudo apt install build-essential devscripts
   sudo apt build-dep pipewire
   

2. Install libfdk-aac-dev

   sudo apt install libfdk-aac-dev
   

   If the above doesn t work you ll likely need to enable non-free and try again

   sudo sed -i 's/main/main non-free/g' /etc/apt/sources.list
   sudo apt update
   

   Alternatively, if you wish to ensure you are maximally license-compliant and patent un-infringing³, you can instead build fdk-aac-free which includes only those components of AAC that are known to be patent-free³. This is what should eventually end up in Debian to resolve this problem (see below).

   sudo apt install git-buildpackage
   mkdir fdk-aac-source
   cd fdk-aac-source
   git clone https://salsa.debian.org/multimedia-team/fdk-aac
   cd fdk-aac
   gbp buildpackage
   sudo dpkg -i ../libfdk-aac2_*deb ../libfdk-aac-dev_*deb
   

3. Get the pipewire source code

   mkdir pipewire-source
   cd pipewire-source
   apt source pipewire
   

   This will create a bunch of files within the pipewire-source directory, but you ll only need the pipewire-<version> folder, this contains all the files you ll need to build the package, with all the debian-specific patches already applied. Note that you don t want to run the apt source command as root, as it will then create files that your regular user cannot edit.
4. Fix the dependencies and build options To fix up the build scripts to use the fdk-aac library, you need to save the following as pipewire-source/aac.patch

   --- debian/control.orig
   +++ debian/control
   @@ -40,8 +40,8 @@
                modemmanager-dev,
                pkg-config,
                python3-docutils,
   -               systemd [linux-any]
   -Build-Conflicts: libfdk-aac-dev
   +               systemd [linux-any],
   +               libfdk-aac-dev
    Standards-Version: 4.6.2
    Vcs-Browser: https://salsa.debian.org/utopia-team/pipewire
    Vcs-Git: https://salsa.debian.org/utopia-team/pipewire.git
   --- debian/rules.orig
   +++ debian/rules
   @@ -37,7 +37,7 @@
    		-Dauto_features=enabled \
    		-Davahi=enabled \
    		-Dbluez5-backend-native-mm=enabled \
   -		-Dbluez5-codec-aac=disabled \
   +		-Dbluez5-codec-aac=enabled \
    		-Dbluez5-codec-aptx=enabled \
    		-Dbluez5-codec-lc3=enabled \
    		-Dbluez5-codec-lc3plus=disabled \
   

   Then you ll need to run patch from within the pipewire-<version> folder created by apt source:

   patch -p0 < ../aac.patch
   

5. Build pipewire

   cd pipewire-*
   debuild
   

   Note that you will likely see an error from debsign at the end of this process, this is harmless, you simply don t have a GPG key set up to sign your newly-built package⁴. Packages don t need to be signed to be installed, and debsign uses a somewhat non-standard signing process that dpkg does not check anyway.

1. Install libspa-0.2-bluetooth

   sudo dpkg -i libspa-0.2-bluetooth_*.deb
   

2. Restart PipeWire and/or Reboot

   sudo reboot
   

   Theoretically there s a set of services to restart here that would get pipewire to pick up the new library, probably just pipewire itself. But it s just as easy to restart and ensure everything is using the correct library.

Why This is a slightly unusual situation, as the fdk-aac library is licensed under what even the GNU project acknowledges is a free software license. However, this license explicitly informs the user that they need to acquire a patent license to use this software⁵:

3. NO PATENT LICENSE NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with respect to this software. You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized by appropriate patent licenses.

To quote the GNU project:

Because of this, and because the license author is a known patent aggressor, we encourage you to be careful about using or redistributing software under this license: you should first consider whether the licensor might aim to lure you into patent infringement.

AAC is covered by a number of patents, which expire at some point in the 2030s⁶. As such the current version of the library is potentially legally dubious to ship with any other software, as it could be considered patent-infringing³.

Fedora s solution Since 2017, Fedora has included a modified version of the library as fdk-aac-free, see the announcement and the bugzilla bug requesting review. This version of the library includes only the AAC LC profile, which is believed to be entirely patent-free³. Based on this, there is an open bug report in Debian requesting that the fdk-aac package be moved to the main component and that the pipwire package be updated to build against it.

The Debian NEW queue To resolve these bugs, a version of fdk-aac-free has been uploaded to Debian by Jeremy Bicha. However, to make it into Debian proper, it must first pass through the ftpmaster s NEW queue. The current version of fdk-aac-free has been in the NEW queue since July 2023. Based on conversations in some of the bugs above, it s been there since at least 2022⁷. I hope this helps anyone stuck with AAC to get their hardware working for them while we wait for the package to eventually make it through the NEW queue. Discuss on Hacker News

1. Such as, for example, any Apple AirPods, which only support AAC AFAICT.
2. Which, as of Debian 12 is GNOME 3 under Wayland with PipeWire.
3. I m not a lawyer, I don t know what kinds of infringement might or might not be possible here, do your own research, etc. ^{2 3 4}
4. And if you DO have a key setup with debsign you almost certainly don t need these instructions.
5. This was originally phrased as explicitly does not grant any patent rights. It was pointed out on Hacker News that this is not exactly what it says, as it also includes a specific note that you ll need to acquire your own patent license. I ve now quoted the relevant section of the license for clarity.
6. Wikipedia claims the base patents expire in 2031, with the extensions expiring in 2038, but its source for these claims is some guy s spreadsheet in a forum. The same discussion also brings up Wikipedia s claim and casts some doubt on it, so I m not entirely sure what s correct here, but I didn t feel like doing a patent deep-dive today. If someone can provide a clear answer that would be much appreciated.
7. According to Jeremy B cha: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1021370#17

1. Raspberry Pi OS has, for years now, specified that there is no upgrade path. That is, to get to a newer major release, it s a reinstall. While I have sometimes worked around this, for a device that is frequently installed in hard-to-reach locations, this is even more important than usual. It s common for me to upgrade machines for a decade or more across Debian releases and there s no reason that it should be so much more difficult with Raspbian.
2. As I noted in Consider Security First, the security situation for Raspberry Pi OS isn t as good as it is with Debian.
3. Raspbian lags behind Debian often times by 6 months or more for major releases, and days or weeks for bug fixes and security patches.
4. Raspbian has no direct backports support, though Raspberry Pi 3 and above can use Debian s backports (per my instructions as Installing Debian Backports on Raspberry Pi)
5. Raspbian uses a custom kernel without initramfs support

WARNINGS Before continuing, back up your system. This process isn t for the neophyte and it is entirely possible to mess up your boot device to the point that you have to do a fresh install to get your Pi to boot. This isn t a supported process at all.

Architecture Confusion Debian has three ARM-based architectures:

• armel, for the lowest-end 32-bit ARM devices without hardware floating point support
• armhf, for the higher-end 32-bit ARM devices with hardware float (hence hf )
• arm64, for 64-bit ARM devices (which all have hardware float)

Although the Raspberry Pi 0 and 1 do support hardware float, they lack support for other CPU features that Debian s armhf architecture assumes. Therefore, the Raspberry Pi 0 and 1 could only run Debian s armel architecture. Raspberry Pi 3 and above are capable of running 64-bit, and can run both armhf and arm64. Prior to the release of the Raspberry Pi 5 / Raspbian bookworm, Raspbian only shipped the armhf architecture. Well, it was an architecture they called armhf, but it was different from Debian s armhf in that everything was recompiled to work with the more limited set of features on the earlier Raspberry Pi boards. It was really somewhere between Debian s armel and armhf archs. You could run Debian armel on those, but it would run more slowly, due to doing floating point calculations without hardware support. Debian s raspi FAQ goes into this a bit. What I am going to describe here is going from Raspbian armhf to Debian armhf with a 64-bit kernel. Therefore, it will only work with Raspberry Pi 3 and above. It may theoretically be possible to take a Raspberry Pi 2 to Debian armhf with a 32-bit kernel, but I haven t tried this and it may be more difficult. I have seen conflicting information on whether armhf really works on a Pi 2. (If you do try it on a Pi 2, ignore everything about arm64 and 64-bit kernels below, and just go with the linux-image-armmp-lpae kernel per the ARMMP page) There is another wrinkle: Debian doesn t support running 32-bit ARM kernels on 64-bit ARM CPUs, though it does support running a 32-bit userland on them. So we will wind up with a system with kernel packages from arm64 and everything else from armhf. This is a perfectly valid configuration as the arm64 like x86_64 is multiarch (that is, the CPU can natively execute both the 32-bit and 64-bit instructions). (It is theoretically possible to crossgrade a system from 32-bit to 64-bit userland, but that felt like a rather heavy lift for dubious benefit on a Pi; nevertheless, if you want to make this process even more complicated, refer to the CrossGrading page.)

Prerequisites and Limitations In addition to the need for a Raspberry Pi 3 or above in order for this to work, there are a few other things to mention. If you are using the GPIO features of the Pi, I don t know if those work with Debian. I think Raspberry Pi OS modified the desktop environment more than other components. All of my Pis are headless, so I don t know if this process will work if you use a desktop environment. I am assuming you are booting from a MicroSD card as is typical in the Raspberry Pi world. The Pi s firmware looks for a FAT partition (MBR type 0x0c) and looks within it for boot information. Depending on how long ago you first installed an OS on your Pi, your /boot may be too small for Debian. Use df -h /boot to see how big it is. I recommend 200MB at minimum. If your /boot is smaller than that, stop now (or use some other system to shrink your root filesystem and rearrange your partitions; I ve done this, but it s outside the scope of this article.) You need to have stable power. Once you begin this process, your pi will mostly be left in a non-bootable state until you finish. (You did make a backup, right?)

Basic idea The basic idea here is that since bookworm has almost entirely newer packages then bullseye, we can just switch over to it and let the Debian packages replace the Raspbian ones as they are upgraded. Well, it s not quite that easy, but that s the main idea.

Preparation First, make a backup. Even an image of your MicroSD card might be nice. OK, I think I ve said that enough now. It would be a good idea to have a HDMI cable (with the appropriate size of connector for your particular Pi board) and a HDMI display handy so you can troubleshoot any bootup issues with a console.

Preparation: access The Raspberry Pi OS by default sets up a user named pi that can use sudo to gain root without a password. I think this is an insecure practice, but assuming you haven t changed it, you will need to ensure it still works once you move to Debian. Raspberry Pi OS had a patch in their sudo package to enable it, and that will be removed when Debian s sudo package is installed. So, put this in /etc/sudoers.d/010_picompat:

pi ALL=(ALL) NOPASSWD: ALL

Also, there may be no password set for the root account. It would be a good idea to set one; it makes it easier to log in at the console. Use the passwd command as root to do so.

Preparation: bluetooth Debian doesn t correctly identify the Bluetooth hardware address. You can save it off to a file by running hcitool dev > /root/bluetooth-from-raspbian.txt. I don t use Bluetooth, but this should let you develop a script to bring it up properly.

Preparation: Debian archive keyring You will next need to install Debian s archive keyring so that apt can authenticate packages from Debian. Go to the bookworm download page for debian-archive-keyring and copy the URL for one of the files, then download it on the pi. For instance:

wget http://http.us.debian.org/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2023.3+deb12u1_all.deb

Use sha256sum to verify the checksum of the downloaded file, comparing it to the package page on the Debian site. Now, you ll install it with:

dpkg -i debian-archive-keyring_2023.3+deb12u1_all.deb

Package first steps From here on, we are making modifications to the system that can leave it in a non-bootable state. Examine /etc/apt/sources.list and all the files in /etc/apt/sources.list.d. Most likely you will want to delete or comment out all lines in all files there. Replace them with something like:

deb http://deb.debian.org/debian/ bookworm main non-free-firmware contrib non-free
deb http://security.debian.org/debian-security bookworm-security main non-free-firmware contrib non-free
deb https://deb.debian.org/debian bookworm-backports main non-free-firmware contrib non-free

(you might leave off contrib and non-free depending on your needs) Now, we re going to tell it that we ll support arm64 packages:

dpkg --add-architecture arm64

And finally, download the bookworm package lists:

apt-get update

If there are any errors from that command, fix them and don t proceed until you have a clean run of apt-get update.

Moving /boot to /boot/firmware The boot FAT partition I mentioned above is mounted at /boot by Raspberry Pi OS, but Debian s scripts assume it will be at /boot/firmware. We need to fix this. First:

umount /boot
mkdir /boot/firmware

Now, edit fstab and change the reference to /boot to be to /boot/firmware. Now:

mount -v /boot/firmware
cd /boot/firmware
mv -vi * ..

This mounts the filesystem at the new location, and moves all its contents back to where apt believes it should be. Debian s packages will populate /boot/firmware later.

Installing the first packages Now we start by installing the first of the needed packages. Eventually we will wind up with roughly the same set Debian uses.

apt-get install linux-image-arm64
apt-get install firmware-brcm80211=20230210-5
apt-get install raspi-firmware

If you get errors relating to firmware-brcm80211 from any commands, run that install firmware-brcm80211 command and then proceed. There are a few packages that Raspbian marked as newer than the version in bookworm (whether or not they really are), and that s one of them.

Configuring the bootloader We need to configure a few things in /etc/default/raspi-firmware before proceeding. Edit that file. First, uncomment (or add) a line like this:

KERNEL_ARCH="arm64"

Next, in /boot/cmdline.txt you can find your old Raspbian boot command line. It will say something like:

root=PARTUUID=...

Save off the bit starting with PARTUUID. Back in /etc/default/raspi-firmware, set a line like this:

ROOTPART=PARTUUID=abcdef00

(substituting your real value for abcdef00). This is necessary because the microSD card device name often changes from /dev/mmcblk0 to /dev/mmcblk1 when switching to Debian s kernel. raspi-firmware will encode the current device name in /boot/firmware/cmdline.txt by default, which will be wrong once you boot into Debian s kernel. The PARTUUID approach lets it work regardless of the device name.

Purging the Raspbian kernel Run:

dpkg --purge raspberrypi-kernel

Upgrading the system At this point, we are going to run the procedure beginning at section 4.4.3 of the Debian release notes. Generally, you will do:

apt-get -u upgrade
apt full-upgrade

Fix any errors at each step before proceeding to the next. Now, to remove some cruft, run:

apt-get --purge autoremove

Inspect the list to make sure nothing important isn t going to be removed.

Removing Raspbian cruft You can list some of the cruft with:

apt list '~o'

And remove it with:

apt purge '~o'

I also don t run Bluetooth, and it seemed to sometimes hang on boot becuase I didn t bother to fix it, so I did:

apt-get --purge remove bluez

Installing some packages This makes sure some basic Debian infrastructure is available:

apt-get install wpasupplicant parted dosfstools wireless-tools iw alsa-tools
apt-get --purge autoremove

Installing firmware Now run:

apt-get install firmware-linux

Resolving firmware package version issues If it gives an error about the installed version of a package, you may need to force it to the bookworm version. For me, this often happened with firmware-atheros, firmware-libertas, and firmware-realtek. Here s how to resolve it, with firmware-realtek as an example:

1. Go to https://packages.debian.org/PACKAGENAME for instance, https://packages.debian.org/firmware-realtek. Note the version number in bookworm in this case, 20230210-5.
2. Now, you will force the installation of that package at that version:

   apt-get install firmware-realtek=20230210-5
   

3. Repeat with every conflicting package until done.
4. Rerun apt-get install firmware-linux and make sure it runs cleanly.

Also, in the end you should be able to:

apt-get install firmware-atheros firmware-libertas firmware-realtek firmware-linux

Dealing with other Raspbian packages The Debian release notes discuss removing non-Debian packages. There will still be a few of those. Run:

apt list '?narrow(?installed, ?not(?origin(Debian)))'

Deal with them; mostly you will need to force the installation of a bookworm version using the procedure in the section Resolving firmware package version issues above (even if it s not for a firmware package). For non-firmware packages, you might possibly want to add --mark-auto to your apt-get install command line to allow the package to be autoremoved later if the things depending on it go away. If you aren t going to use Bluetooth, I recommend apt-get --purge remove bluez as well. Sometimes it can hang at boot if you don t fix it up as described above.

Set up networking We ll be switching to the Debian method of networking, so we ll create some files in /etc/network/interfaces.d. First, eth0 should look like this:

allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 auto

And wlan0 should look like this:

allow-hotplug wlan0
iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Raspbian is inconsistent about using eth0/wlan0 or renamed interface. Run ifconfig or ip addr. If you see a long-named interface such as enx<something> or wlp<something>, copy the eth0 file to the one named after the enx interface, or the wlan0 file to the one named after the wlp interface, and edit the internal references to eth0/wlan0 in this new file to name the long interface name. If using wifi, verify that your SSIDs and passwords are in /etc/wpa_supplicant/wpa_supplicant.conf. It should have lines like:

network= 
   ssid="NetworkName"
   psk="passwordHere"
 

(This is where Raspberry Pi OS put them).

Deal with DHCP Raspberry Pi OS used dhcpcd, whereas bookworm normally uses isc-dhcp-client. Verify the system is in the correct state:

apt-get install isc-dhcp-client
apt-get --purge remove dhcpcd dhcpcd-base dhcpcd5 dhcpcd-dbus

Set up LEDs To set up the LEDs to trigger on MicroSD activity as they did with Raspbian, follow the Debian instructions. Run apt-get install sysfsutils. Then put this in a file at /etc/sysfs.d/local-raspi-leds.conf:

class/leds/ACT/brightness = 1
class/leds/ACT/trigger = mmc1

Prepare for boot To make sure all the /boot/firmware files are updated, run update-initramfs -u. Verify that root in /boot/firmware/cmdline.txt references the PARTUUID as appropriate. Verify that /boot/firmware/config.txt contains the lines arm_64bit=1 and upstream_kernel=1. If not, go back to the section on modifying /etc/default/raspi-firmware and fix it up.

The moment arrives Cross your fingers and try rebooting into your Debian system:

reboot

For some reason, I found that the first boot into Debian seems to hang for 30-60 seconds during bootstrap. I m not sure why; don t panic if that happens. It may be necessary to power cycle the Pi for this boot.

Troubleshooting If things don t work out, hook up the Pi to a HDMI display and see what s up. If I anticipated a particular problem, I would have documented it here (a lot of the things I documented here are because I ran into them!) So I can t give specific advice other than to watch boot messages on the console. If you don t even get kernel messages going, then there is some problem with your partition table or /boot/firmware FAT partition. Otherwise, you ve at least got the kernel going and can troubleshoot like usual from there.

Couldn't get a file descriptor referring to the console.

How does Shell Initialization Work? The precise files a shell reads at start-up is somewhat complex, and defined by this excellent chart ¹: For the purposes of what I m trying to fix, there are two paths that matter.

• Interactive login shell startup
• Interactive non-login shell startup

As you can see from the above, trying to distinguish these two paths in bash is an absolute mess. zsh, in contrast, is much cleaner and allows for a clear distinction between these two cases, with login shell configuration files as a superset of configuration files used by non-login shells.

How did we get here? I keep my configuration files in a config repository. Some time ago I got quite frustrated at this whole shell initialization thing, and just linked everything together in one profile file:

.mkshrc -> config/profile
.profile -> config/profile

This appears to have created this mess.

Move to ZSH I ve wanted to move to zsh for a while, and took this opportunity to do so. So my new configuration files are .zprofile and .zshrc instead of .mkshrc and .profile (though I m going to retain those symlinks to allow my old configurations to continue working). mksh is a nice simple shell, but using zsh here allows for more consistency between my home and $WORK environments, and will allow a lot more powerful extensions.

Updating my Prompt ZSH prompts use a totally different configuration via variable expansion. However, it also uses the PROMPT variable, so I set that to the needed values for zsh. There s an excellent ZSH prompt generator at https://zsh-prompt-generator.site that I used to get these variables, though I m sure they re in the zsh documentation somewhere as well. I wanted a simple prompt with user (%n), host (%m), and path (%d). I also wanted a % at the end to distinguish this from other shells.

PROMPT="%n@%m%d%% "

Fixing mksh prompts This worked but surprisingly mksh also looks at PROMPT, leaving my mksh prompt as the literal prompt string without expansion. Fixing this requires setting up a proper shrc and linking it to .mkshrc and .zshrc. I chose to move my existing aliases script to this file, as it also broke in non-login shells when moved to profile. Within this new shrc file we can check what shell we re running via $0:

if [ "$0" = "/bin/zsh" ]   [ "$0" = "zsh" ]   [ "$0" = "-zsh" ]

I chose to add plain zsh here in case I run it manually for whatever reason. I also added -zsh to support tmux as that s what it presents as $0. This also means you ll need to be careful to quote $0 or you ll get fun shell errors. There s probably a better way to do this, but I couldn t find something that was compatible with POSIX shell, which is what most of this has to be written in to be compatible with mksh and zsh². We can then setup different prompts for each:

if [ "$0" = "/bin/zsh" ]   [ "$0" = "zsh" ]   [ "$0" = "-zsh" ]
then
	PROMPT="%n@%m%d%% "
else
	# Borrowed from
	# http://www.unixmantra.com/2013/05/setting-custom-prompt-in-ksh.html
	PS1='$(id -un)@$(hostname -s)$PWD$ '
fi

Setting Console Font in a Better Way I ve been setting console font via setfont in my .profile for a while. I m not sure where I picked this up, but it s not the right way. I even tried to only run this in a console with -t but that only checks that output is a terminal, not specifically a console.

if [ -t 1 ]
then
	setfont /usr/share/consolefonts/Lat15-Terminus20x10.psf.gz
fi

This also only runs once the console is logged into, instead of initializing it on boot. The correct way to set this up, on Debian-based systems, is reconfiguring console-setup like so:

dpkg-reconfigure console-setup

From there you get a menu of encoding, character set, font, and then font size to configure for your consoles.

VIM mode To enable VIM mode for ZSH, you simply need to set:

bindkeys -v

This allows you to edit your shell commands with basic VIM keybinds.

Getting back Ctrl + Left Arrow and Ctrl + Right Arrow Moving around one word at a time with Ctrl and the arrow keys is broken by vim mode unfortunately, so we ll need to re-enable it:

bindkey "^[[1;5C" forward-word
bindkey "^[[1;5D" backward-word

Better History Search But of course we re now using zsh so we can do better than just the same configuration as we had before. There s an excellent substring history search plugin that we can just source without a plugin manager³

source $HOME/config/zsh-history-substring-search.zsh
# Keys are weird, should be ^[[ but it's not
bindkey '^[[A' history-substring-search-up
bindkey '^[OA' history-substring-search-up
bindkey '^[[B' history-substring-search-down
bindkey '^[OB' history-substring-search-down

For some reason my system uses ^[OA and ^[OB as up and down keys. It seems ^[[A and ^[[B are the defaults, so I ve left them in, but I m confused as to what differences would lead to this. If you know, please let me know and I ll add a footnote to this article explaining it. Back to history search. For this to work, we also need to setup history logging:

export SAVEHIST=1000000
export HISTFILE=$HOME/.zsh_history
export HISTFILESIZE=1000000
export HISTSIZE=1000000

Why did it show up twice for tmux? Because tmux creates a login shell. Adding:

echo PROFILE

to profile and:

echo SHRC

to shrc confirms this with:

PROFILE
SHRC
SHRC

For now, profile sources shrc so that running twice is expected. But after this exploration and diagram, it s clear we don t need that for zsh. Removing this will break remote bash shells (see above diagram), but I can live without those on my development laptop. Removing that line results in the expected output for a new terminal:

SHRC

And the full output for a new tmux session or console:

PROFILE
SHRC

So finally we re back to a normal state! This post is a bit unfocused but I hope it helps someone else repair or enhance their shell environment. If you liked this⁴, or know of any other ways to manage this I could use, let me know at fixmyshell@tookmund.com.

1. This chart comes from the excellent Shell Startup Scripts article by Peter Ward. I ve generated the SVG from the graphviz source linked in the article.
2. Technically it has be compatible with Korn shell, but a quick google seems to suggest that that s actually a subset of POSIX shell.
3. I use oh-my-zsh at $WORK but for now I m going to simplify my personal configuration. If I end up using a lot of plugins I ll reconsider this.
4. Or if you ve found any typos or other issues that I should fix.

Focus This month I didn't have any particular focus. I just worked on issues in my info bubble.

Changes

• swh-web: direct replies better, strip whitespace
• Debian screenshots:
  • deleted freecell-solver-bin (not a graphical program)
• Debian BTS usertags: fix ports/archive usertags
• Debian wiki pages: DebianAlternatives, LoongArch, Mobian/Devices, Software that can't be packaged, Statistics, Teams/Cinnamon
• FOSSjobs wiki pages: Resources

Issues

• Feature in UDD
• Conffile removal needed in neomutt
• dpkg vendor config needed in Armbian
• New SWH listers needed for depp & depp (different projects)

Review

• Debian packages: sponsored harmony
• Debian wiki: RecentChanges for the month
• Debian BTS usertags: changes for the month
• Debian screenshots:
  • approved fonts-arphic-bkai00mp fonts-dejavu fonts-freefont-ttf fonts-liberation-sans-narrow fonts-mathjax fonts-noto-cjk fonts-noto-mono fonts-quicksand fonts-urw-base35 freecol lincity-ng qnetload
  • rejected librte-bbdev0.200 (library with no UI), freecell-solver-bin (not a graphical program)

Administration

• Debian wiki: approve accounts

Communication

• Respond to queries from Debian users and contributors on the mailing lists and IRC

Sponsors The SWH work was sponsored. All other work was done on a volunteer basis.

# sudo apt install licenserecon
jas@kaka:~/dpkg/resolv-wrapper$ lrc
Parsing Source Tree ....
Running licensecheck ....
d/copyright       licensecheck
BSD-3-Clauses     BSD-3-clause     src/resolv_wrapper.c
BSD-3-Clauses     BSD-3-clause     tests/dns_srv.c
BSD-3-Clauses     BSD-3-clause     tests/test_dns_fake.c
BSD-3-Clauses     BSD-3-clause     tests/test_res_query_search.c
BSD-3-Clauses     BSD-3-clause     tests/torture.c
BSD-3-Clauses     BSD-3-clause     tests/torture.h
jas@kaka:~/dpkg/resolv-wrapper$ 

---
include:
  - https://salsa.debian.org/salsa-ci-team/pipeline/raw/master/recipes/debian.yml
  - https://salsa.debian.org/debian/licenserecon/raw/main/debian/licenserecon.yml

$ cd $ WORKING_DIR /$ SOURCE_DIR 
$ lrc
Parsing Source Tree ....
Running licensecheck ....
No differences found
Cleaning up project directory and file based variables

• Struggling with Debian source packages?
• Just use dgit
• Objections
  • But I don t want to learn yet another tool
  • Shouldn t I be using official Debian git repos?
  • Gosh, is Debian really this bad?
  • I m a Debian maintainer. You tell me dgit is something totally different!

1. By default dgit fetches from Debian unstable, the main work-in-progress branch. You may want something like dgit clone PACKAGE bookworm,-security (yes, with a comma).
2. You probably want to edit debian/changelog to make your packages have a different version number.
3. To build binaries, run dpkg-buildpackage -uc -b.
4. Debian package builds are often disastrously messsy: builds might modify source files; and the official debian/rules clean can be inadequate, or crazy. Always commit before building, and use git clean and git reset --hard instead of running clean rules from the package.

#!/bin/sh
if [ "$0" = "/etc/kernel/postinst.d/reboot-notifier" ]; then
    DPKG_MAINTSCRIPT_PACKAGE=linux-base
fi
echo "*** System restart required ***" > /var/run/reboot-required
echo "$DPKG_MAINTSCRIPT_PACKAGE" >> /var/run/reboot-required.pkgs

#!/bin/sh
case "$DPKG_MAINTSCRIPT_PACKAGE::$DPKG_MAINTSCRIPT_NAME" in
   linux-image-extra*::postrm)
      exit 0;;
esac
if [ -d /var/run ]; then
    touch /var/run/reboot-required
    if ! grep -q "^$DPKG_MAINTSCRIPT_PACKAGE$" /var/run/reboot-required.pkgs 2> /dev/null ; then
        echo "$DPKG_MAINTSCRIPT_PACKAGE" >> /var/run/reboot-required.pkgs
    fi
fi

#!/bin/bash
REBOOT_REQUIRED=/var/run/reboot-required
if [ -s $REBOOT_REQUIRED ] ; then
    cat "$REBOOT_REQUIRED"   /usr/bin/mail -s "Rebooting $HOSTNAME" root
    /bin/systemctl reboot
fi