Search Results: "spa"

21 September 2025

Gunnar Wolf: We, Programmers A Chronicle of Coders from Ada to AI

This post is a review for Computing Reviews for We, Programmers A Chronicle of Coders from Ada to AI , a book published in Addison-Wesley
When this book was presented as available for review, I jumped on it. After all, who doesn t love reading a nice bit of computing history, as told by a well-known author (affectionaly known as Uncle Bob ), one who has been immersed in computing since forever? What s not to like there? Reading on, the book does not disappoint. Much to the contrary, it digs into details absent in most computer history books that, being an operating systems and computer architecture geek, I absolutely enjoyed. But let me first address the book s organization. The book is split into four parts. Part 1, Setting the Stage, is a short introduction, answering the question Who are we? ( we being the programmers, of course). It describes the fascination many of us felt when we realized that the computer was there to obey us, to do our bidding, and we could absolutely control it. Part 2 talks about the giants of the computing world, on whose shoulders we stand. It digs in with a level of detail I have never seen before, discussing their personal lives and technical contributions (as well as the hoops they had to jump through to get their work done). Nine chapters cover these giants, ranging chronologically from Charles Babbage and Ada Lovelace to Ken Thompson, Dennis Richie, and Brian Kernighan (understandably, giants who worked together are grouped in the same chapter). This is the part with the most historically overlooked technical details. For example, what was the word size in the first computers, before even the concept of a byte had been brought into regular use? What was the register structure of early central processing units (CPUs), and why did it lead to requiring self-modifying code to be able to execute loops? Then, just as Unix and C get invented, Part 3 skips to computer history as seen through the eyes of Uncle Bob. I must admit, while the change of rhythm initially startled me, it ends up working quite well. The focus is no longer on the giants of the field, but on one particular person (who casts a very long shadow). The narrative follows the author s life: a boy with access to electronics due to his father s line of work; a computing industry leader, in the early 2000s, with extreme programming; one of the first producers of training materials in video format a role that today might be recognized as an influencer. This first-person narrative reaches year 2023. But the book is not just a historical overview of the computing world, of course. Uncle Bob includes a final section with his thoughts on the future of computing. As this is a book for programmers, it is fitting to start with the changes in programming languages that we should expect to see and where such changes are likely to take place. The unavoidable topic of artificial intelligence is presented next: What is it and what does it spell for computing, and in particular for programming? Interesting (and sometimes surprising) questions follow: What does the future of hardware development look like? What is prone to be the evolution of the World Wide Web? What is the future of programming and programmers? At just under 500 pages, the book is a volume to be taken seriously. But space is very well used with this text. The material is easy to read, often funny and always informative. If you enjoy computer history and understanding the little details in the implementations, it might very well be the book you want.

Joey Hess: cheap DIY solar fence design

A year ago I installed a 4 kilowatt solar fence. I'm revisiting it this Sun Day, to share the design, now that I have prooved it out.
The solar fence and some other ground and pole mount solar panels, seen through leaves.
Solar fencing manufacturers have some good simple designs, but it's hard to buy for a small installation. They are selling to utility scale solar mostly. And those are installed by driving metal beams into the ground, which requires heavy machinery. Since I have experience with Ironridge rails for roof mount solar, I decided to adapt that system for a vertical mount. Which is something it was not designed for. I combined the Ironridge hardware with regular parts from the hardware store. The cost of mounting solar panels nowadays is often higher than the cost of the panels. I hoped to match the cost, and I nearly did. The solar panels cost $100 each, and the fence cost $110 per solar panel. This fence was significantly cheaper than conventional ground mount arrays that I considered as alternatives, and made a better use of a difficult hillside location. I used 7 foot long Ironridge XR-10 rails, which fit 2 solar panels per rail. (Longer rails would need a center post anyway, and the 7 foot long rails have cheaper shipping, since they do not need to be shipped freight.) For the fence posts, I used regular 4x4" treated posts. 12 foot long, set in 3 foot deep post holes, with 3x 50 lb bags of concrete per hole and 6 inches of gravel on the bottom.
detail of how the rails are mounted to the posts, and the panels to the rails
To connect the Ironridge rails to the fence posts, I used the Ironridge LFT-03-M1 slotted L-foot bracket. Screwed into the post with a 5/8 x 3 inch hot-dipped galvanized lag screw. Since a treated post can react badly with an aluminum bracket, there needs to be some flashing between the post and bracket. I used Shurtape PW-100 tape for that. I see no sign of corrosion after 1 year. The rest of the Ironridge system is a T-bolt that connects the rail to the L-foot (part BHW-SQ-02-A1), and Ironridge solar panel fasteners (UFO-CL-01-A1 and UFO-STP-40MM-M1). Also XR-10 end caps and wire clips. Since the Ironridge hardware is not designed to hold a solar panel at a 90 degree angle, I was concerned that the panels might slide downward over time. To help prevent that, I added some additional support brackets under the bottom of the panels. So far, that does not seem to have been a problem though. I installed Aptos 370 watt solar panels on the fence. They are bifacial, and while the posts block the back partially, there is still bifacial gain on cloudy days. I left enough space under the solar panels to be able to run a push mower under them.
Me standing in front of the solar fence at end of construction
I put pairs of posts next to one-another, so each 7 foot segment of fence had its own 2 posts. This is the least elegant part of this design, but fitting 2 brackets next to one-another on a single post isn't feasible. I bolted the pairs of posts together with some spacers. A side benefit of doing it this way is that treated lumber can warp as it dries, and this prevented much twisting of the posts. Using separate posts for each segment also means that the fence can traverse a hill easily. And it does not need to be perfectly straight. In fact, my fence has a 30 degree bend in the middle. This means it has both south facing and south-west facing panels, so can catch the light for longer during the day. After building the fence, I noticed there was a slight bit of sway at the top, since 9 feet of wooden post is not entirely rigid. My worry was that a gusty wind could rattle the solar panels. While I did not actually observe that happening, I added some diagonal back bracing for peace of mind.
view of rear upper corner of solar fence, showing back bracing connection
Inspecting the fence today, I find no problems after the first year. I hope it will last 30 years, with the lifespan of the treated lumber being the likely determining factor. As part of my larger (and still ongoing) ground mount solar install, the solar fence has consistently provided great power. The vertical orientation works well at latitude 36. It also turned out that the back of the fence was useful to hang conduit and wiring and solar equipment, and so it turned into the electrical backbone of my whole solar field. But that's another story.. solar fence parts list
quantity cost per unit description
10 $27.89 7 foot Ironridge XR-10 rail
12 $20.18 12 foot treated 4x4
30 $4.86 Ironridge UFO-CL-01-A1
20 $0.87 Ironridge UFO-STP-40MM-M1
1 $12.62 Ironridge XR-10 end caps (20 pack)
20 $2.63 Ironridge LFT-03-M1
20 $1.69 Ironridge BHW-SQ-02-A1
22 $2.65 5/8 x 3 inch hot-dipped galvanized lag screw
10 $0.50 6 gravel per post
30 $6.91 50 lb bags of quickcrete
1 $15.00 Shurtape PW-100 Corrosion Protection Pipe Wrap Tape
N/A $30 other bolts and hardware (approximate)
$1100 total (Does not include cost of panels, wiring, or electrical hardware.)

Jonathan Dowland: Lavalamps (things that spark joy)

photograph of a Mathmos Telstar rocket lava lamp with red wax and purple water
Life can sometimes be tricky, and it's useful to know that there are some simple things to take pleasure from. Amongst them for me are lava lamps. At some point in the late 90s, my brother and I somehow had 6 lavalamps between us. I'm not sure what happened to them (and the gallery of photos I had of them has long disappeared from my site.) More recently, I stumbled across a Mathmos "Telstar" rocket-shaped lava lamp in a charity shop: silver metal; purple water; red wax. It now adorns my study desk.

20 September 2025

Thomas Goirand: Real-Time OpenStack Packaging Status with Event-Driven Automation

tl;dr: https://osbpo.debian.net/deb-status is now real-time updated and much better than it used to, helping the OpenStack packaging team be a way more efficient.
How it used to be For years, the Debian OpenStack team has relied on automated tools to track the status of OpenStack packages across Debian releases. Our goal has always been simple: transparency, efficiency, accuracy. We used to use a tool called os-version-checker, written by Michal Arbet, which generated a static status page at https://osbpo.debian.net/deb-status. It was functional and served us well but it had limitations: This meant that when a developer pushed a new package to salsa (the Debian GitLab instance) in the team s repository, the following would happen: For maintainers actively working on a new release, this delay was frustrating. You d fix a bug, push, build and still see your package marked as missing or out of date for minutes. You had no real-time feedback. This was also an annoyance for testing, because when fixing a bug, I often had to trigger the rsync manually in order to not wait for it, so I could do my tests. Now, osbpo is always up-to-date a few seconds after the build of the package. The New Way: Event-Driven, Real-Time Updates We ve rebuilt the system from the ground up to be fast, responsive, and event-driven. Now, the workflow is: The webhook on osbpo does: No more cron. No more waiting

How it works The central osbpo.debian.net server runs: Jenkins instances are configured to curl the webhook on successful build. The status page is generated by openstack-debian-release-manager, a new tool I ve packaged and deployed. The dashboard uses AJAX to load content dynamically (like when browsing from one release to another), with sorting, metadata, and real-time auto-refresh every 10 seconds. openstack-debian-release-manager is easy to deploy and configure, and will do most (if not all) of the needed configuration. Uploading it to Debian is probably not needed, and a bit over-kill, so I believe I ll just keep it in Salsa for the moment, unless there s a way to make it more generic so it can help someone else (another team?) in Debian.
Room for improvement There s still things I want to add. Namely: Special thanks to Michal Arbet for the original os-version-checker that served me for years, helping me to never forget a missing OpenStack package release.

18 September 2025

John Goerzen: Running an Accurate 80 25 DOS-Style Console on Modern Linux Is Possible After All

Here, in classic Goerzen deep dive fashion, is more information than you knew you wanted about a topic you ve probably never thought of. I found it pretty interesting, because it took me down a rabbit hole of subsystems I ve never worked with much and a mishmash of 1980s and 2020s tech. I had previously tried and failed to get an actual 80x25 Linux console, but I ve since figured it out! This post is about the Linux text console not X or Wayland. We re going to get the console right without using those systems. These instructions are for Debian trixie, but should be broadly applicable elsewhere also. The end result can look like this: Photo of a color VGA monitor displaying a BBS login screen (That s a Wifi Retromodem that I got at VCFMW last year in the Hayes modem case)

What s a pixel? How would you define a pixel these days? Probably something like a uniquely-addressable square dot in a two-dimensional grid . In the world of VGA and CRTs, that was just a logical abstraction. We got an API centered around that because it was convenient. But, down the VGA cable and on the device, that s not what a pixel was. A pixel, back then, was a time interval. On a multisync monitor, which were common except in the very early days of VGA, the timings could be adjusted which produced logical pixels of different sizes. Those screens often had a maximum resolution but not necessarily a native resolution in the sense that an LCD panel does. Different timings produced different-sized pixels with equal clarity (or, on cheaper monitors, equal fuzziness). A side effect of this was that pixels need not be square. And, in fact, in the standard DOS VGA 80x25 text mode, they weren t. You might be seeing why DVI, DisplayPort, and HDMI replaced VGA for LCD monitors: with a VGA cable, you did a pixel-to-analog-timings conversion, then the display did a timings-to-pixels conversion, and this process could be a bit lossy. (Hence why you sometimes needed to fill the screen with an image and push the center button on those older LCD screens) (Note to the pedantically-inclined: yes I am aware that I have simplified several things here; for instance, a color LCD pixel is made up of approximately 3 sub-dots of varying colors, and that things like color eInk displays have two pixel grids with different sizes of pixels layered atop each other, and printers are another confusing thing altogether, and and and . MOST PEOPLE THINK OF A PIXEL AS A DOT THESE DAYS, OK?)

What was DOS text mode? We think of this as the standard display: 80 columns wide and 25 rows tall. 80x25. By the time Linux came along, the standard Linux console was VGA text mode something like the 4th incarnation of text modes on PCs (after CGA, MDA, and EGA). VGA also supported certain other sizes of characters giving certain other text dimensions, but if I cover all of those, this will explode into a ridiculously more massive page than it already is. So to display text on an 80x25 DOS VGA system, ultimately characters and attributes were written into the text buffer in memory. The VGA system then rendered it to the display as a 720x400 image (at 70Hz) with non-square pixels such that the result was approximately a 4:3 aspect ratio. The font used for this rendering was a bitmapped one using 8x16 cells. You might do some math here and point out that 8 * 80 is only 640, and you d be correct. The fonts were 8x16 but the rendered cells were 9x16. The extra pixel was normally used for spacing between characters. However, in line graphics mode, characters 0xC0 through 0xDF repeated the 8th column in the position of the 9th, allowing the continuous line-drawing characters we re used to from TUIs.

Problems rendering DOS fonts on modern systems By now, you re probably seeing some of the issues we have rendering DOS screens on more modern systems. These aren t new at all; I remember some of these from back in the days when I ran OS/2, and I think also saw them on various terminals and consoles in OS/2 and Windows. Some issues you d encounter would be:
  • Incorrect aspect ratio caused by using the original font and rendering it using 1:1 square pixels (resulting in a squashed appearance)
  • Incorrect aspect ratio for ANOTHER reason, caused by failing to render column 9, resulting in text that is overall too narrow
  • Characters appearing to be touching each other when they shouldn t (failing to render column 9; looking at you, dosbox)
  • Gaps between line drawing characters that should be continuous, caused by rendering column 9 as empty space in all cases

Character set issues DOS was around long before Unicode was. In the DOS world, there were codepages that selected the glyphs for roughly the high half of the 256 possible characters. CP437 was the standard for the USA; others existed for other locations that needed different characters. On Unix, the USA pre-Unicode standard was Latin-1. Same concept, but with different character mappings. Nowadays, just about everything is based on UTF-8. So, we need some way to map our CP437 glyphs into Unicode space. If we are displaying DOS-based content, we ll also need a way to map CP437 characters to Unicode for display later, and we need these maps to match so that everything comes out right. Whew. So, let s get on with setting this up!

Selecting the proper video mode As explained in my previous post, proper hardware support for DOS text mode is limited to x86 machines that do not use UEFI. Non-x86 machines, or x86 machines with UEFI, simply do not contain the necessary support for it. As these are now standard, most of the time, the text console you see on Linux is actually the kernel driving the video hardware in graphics mode, and doing the text rendering in software. That s all well and good, but it makes it quite difficult to actually get an 80x25 console. First, we need to be running at 720x400. This is where I ran into difficulty last time. I realized that my laptop s LCD didn t advertise any video modes other than its own native resolution. However, almost all external monitors will, and 720x400@70 is a standard VGA mode from way back, so it should be well-supported. You need to find the Linux device name for your device. You can look at the possible devices with ls -l /sys/class/drm. If you also have a GUI, xrandr may help too. But in any case, each directory under /sys/class/drm has a file named modes, and if you cat them all, you will eventually come across one with a bunch of modes defined. Drop the leading card0 or whatever from the directory name, and that s your device. (Verify that 720x400 is in modes while you re at it.) Now, you re going to edit /etc/default/grub and add something like this to GRUB_CMDLINE_LINUX_DEFAULT: 
video=DP-1:720x400@70
Of course, replace DP-1 with whatever your device is. Now you can run update-grub and reboot. You should have a 720x400 display. At first, I thought I had succeeded by using Linux s built-in VGA font with that mode. But it looked too tall. After noticing that repeated 0s were touching, I got suspicious about the missing 9th column in the cells. stty -a showed that my screen was 90x25, which is exactly what it would show if I was using 8x16 instead of 9x16 cells. Sooo . I need to prepare a 9x16 font.

Preparing a font Here s where it gets complicated. I ll give you the simple version and the hard mode. The simple mode is this: Download https://www.complete.org/downloads/CP437-VGA.psf.gz and stick it in /usr/local/etc, then skip to the Activating the font section below. The font assembled here is based on the Ultimate Oldschool PC Font Pack v2.2, which is (c) 2016-2020 VileR and licensed under Creative Commons Attribution-ShareAlike 4.0 International License. My psf file is derived from this using the instructions below.

Building it yourself First, install some necessary software: apt-get install fontforge bdf2psf Start by going to the Oldschool PC Font Pack Download page. Download oldschool_pc_font_pack_v2.2_FULL.zip and unpack it. The file we re interested in is otb - Bm (linux bitmap)/Bm437_IBM_VGA_9x16.otb. Open it in fontforge by running fontforge BmPlus_IBM_VGA_9x16.otb. When it asks if you will load the bitmap fonts, hit select all, then yes. Go to File -> generate fonts. Save in a BDF, no need for outlines, and use guess for resolution. Now you have a file such as Bm437_IBM_VGA_9x16-16.bdf. Excellent. Now we need to generate a Unicode map file. We will make sure this matches the system s by enumerating every character from 0x00 to 0xFF, converting it from CP437 to Unicode, and writing the appropriate map. Here s a Python script to do that: 
for i in range(0, 256):
    cp437b = b'%c' % i
    uni = ord(cp437b.decode('cp437'))
    print(f"U+ uni:04x ")
Save that file as genmap.py and run python3 genmap.py > cp437-uni. Now, we re ready to build the psf file: 
bdf2psf --fb Bm437_IBM_VGA_9x16-16.bdf \
  /dev/null cp437-uni 256 CP437-VGA.psf
By convention, we normally store these files gzipped, so gzip CP437-VGA.psf. You can test it on the console with setfont CP437-VGA.psf.gz. Now copy this file into /usr/local/etc.

Activating the font Now, edit /etc/default/console-setup. It should look like this: 
# CONFIGURATION FILE FOR SETUPCON

# Consult the console-setup(5) manual page.

ACTIVE_CONSOLES="/dev/tty[1-6]"

CHARMAP="UTF-8"

CODESET="Lat15"
FONTFACE="VGA"
FONTSIZE="8x16"
FONT=/usr/local/etc/CP437-VGA.psf.gz

VIDEOMODE=

# The following is an example how to use a braille font
# FONT='lat9w-08.psf.gz brl-8x8.psf'
At this point, you should be able to reboot. You should have a proper 80x25 display! Log in and run stty -a to verify it is indeed 80x25.

Using and testing CP437 Part of the point of CP437 is to be able to access BBSs, ANSI art, and similar. Now, remember, the Linux console is still in UTF-8 mode, so we have to translate CP437 to UTF-8, then let our font map translate it back to CP437. A weird trip, but it works. Let s test it using the Textfiles ANSI art collection. In the artworks section, I randomly grabbed a file near the top: borgman.ans. Download that, and display with: 
clear; iconv -f CP437 -t UTF-8 < borgman.ans
You should see something similar to but actually more accurate than the textfiles PNG rendering of it, which you ll note has an incorrect aspect ratio and some rendering issues. I spot-checked with a few others and they seemed to look good. belinda.ans in particular tries quite a few characters and should give you a good sense if it is working.

Use with interactive programs That s all well and good, but you re probably going to want to actually use this with some interactive program that expects CP437. Maybe Minicom, Kermit, or even just telnet? For this, you ll want to apt-get install luit. luit maps CP437 (or any other encoding) to UTF-8 for display, and then of course the Linux console maps UTF-8 back to the CP437 font. Here s a way you can repeat the earlier experiment using luit to run the cat program: 
clear; luit -encoding CP437 cat borgman.ans
You can run any command under luit. You can even run luit -encoding CP437 bash if you like. If you do this, it is probably a good idea to follow my instructions on generating locales on my post on serial terminals, and then within luit, set LANG=en_us.IBM437. But note especially that you can run programs like minicom and others for accessing BBSs under luit.

Final words This gave you a nice DOS-type console. Although it doesn t have glyphs for many codepoints, it does run in UTF-8 mode and therefore is compatible with modern software. You can achieve greater compatibility with more UTF-8 codepoints with the DOS font, at the expense of accuracy of character rendering (especially for the double-line drawing characters) by using /usr/share/bdf2psf/standard.equivalents instead of /dev/null in the bdf2psf command. Or you could go for another challenge, such as using the DEC vt-series fonts for coverage of ISO-8859-1. But just using fonts extracted from DEC ROM won t work properly, because DEC terminals had even more strangeness going on than DOS fonts.

16 September 2025

Raju Devidas: Building Debian 13 Trixie Vagrant Image

I sometimes use Vagrant to deploy my VM&aposs and recently when I tried to deploy one for Trixie, I could see one available. So I checked the official Debian images on Vagrant cloud at https://portal.cloud.hashicorp.com/vagrant/discover/debian and could not find an image for trixie on Vagrant cloud. Also looked at other cloud image sources like Docker hub, and I could see an image their for Trixie. So I looked into how I can generate a Vagrant image locally for Debian to use.
make install-build-deps


Searched on Salsa and stumbled upon https://salsa.debian.org/cloud-team/debian-vagrant-imagesCloned the repo from salsa
$ git clone https://salsa.debian.org/cloud-team/debian-vagrant-images.git
Install the build dependencies
$ make install-build-deps
this will install some dependency packages, will ask for sudo password if need to install something not already installed. Let&aposs call make help 
$ make help
To run this makefile, run:
   make <DIST>-<CLOUD>-<ARCH>
  WHERE <DIST> is bullseye, buster, stretch, sid or testing
    And <CLOUD> is azure, ec2, gce, generic, genericcloud, nocloud, vagrant, vagrantcontrib
    And <ARCH> is amd64, arm64, ppc64el
Set DESTDIR= to write images to given directory.
$ make trixie-vagrant-amd64
umask 022; \
./bin/debian-cloud-images build \
  trixie vagrant amd64 \
  --build-id vagrant-cloud-images-master \
  --build-type official
usage: debian-cloud-images build
debian-cloud-images build: error: argument RELEASE: invalid value: trixie
make: *** [Makefile:22: trixie-vagrant-amd64] Error 2
As you can see, trixie is not even in the available options and it is not building as well. Before trying to look at updating the codebase, I looked at the pending MR&aposs on Salsa and found Michael Ablassmeier&aposs pending merge request at https://salsa.debian.org/cloud-team/debian-vagrant-images/-/merge_requests/18So let me test that commit and see if I can build trixie locally from Michael&aposs MR
$ git clone https://salsa.debian.org/debian/debian-vagrant-images.git
Cloning into &aposdebian-vagrant-images&apos...
remote: Enumerating objects: 5310, done.
remote: Counting objects: 100% (256/256), done.
remote: Compressing objects: 100% (96/96), done.
remote: Total 5310 (delta 141), reused 241 (delta 135), pack-reused 5054 (from 1)
Receiving objects: 100% (5310/5310), 629.81 KiB   548.00 KiB/s, done.
Resolving deltas: 100% (2875/2875), done.
$ cd debian-vagrant-images/
$ git checkout 8975eb0 #the commit id of MR
Now let&aposs see if we can build trixie now
$ make help
To run this makefile, run:
   make <DIST>-<CLOUD>-<ARCH>
  WHERE <DIST> is bullseye, buster, stretch, sid or testing
    And <CLOUD> is azure, ec2, gce, generic, genericcloud, nocloud, vagrant, vagrantcontrib
    And <ARCH> is amd64, arm64, ppc64el
Set DESTDIR= to write images to given directory.
$ make trixie-vagrant-amd64
umask 022; \
./bin/debian-cloud-images build \
  trixie vagrant amd64 \
  --build-id vagrant-cloud-images-master \
  --build-type official
2025-09-17 00:36:25,919 INFO Adding class DEBIAN
2025-09-17 00:36:25,919 INFO Adding class CLOUD
2025-09-17 00:36:25,919 INFO Adding class TRIXIE
2025-09-17 00:36:25,920 INFO Adding class VAGRANT
2025-09-17 00:36:25,920 INFO Adding class AMD64
2025-09-17 00:36:25,920 INFO Adding class LINUX_IMAGE_BASE
2025-09-17 00:36:25,920 INFO Adding class GRUB_PC
2025-09-17 00:36:25,920 INFO Adding class LAST
2025-09-17 00:36:25,921 INFO Running FAI: sudo env PYTHONPATH=/home/rajudev/dev/salsa/michael/debian-vagrant-images/src/debian_cloud_images/build/../.. CLOUD_BUILD_DATA=/home/rajudev/dev/salsa/michael/debian-vagrant-images/src/debian_cloud_images/data CLOUD_BUILD_INFO= "type": "official", "release": "trixie", "release_id": "13", "release_baseid": "13", "vendor": "vagrant", "arch": "amd64", "build_id": "vagrant-cloud-images-master", "version": "20250917-1"  CLOUD_BUILD_NAME=debian-trixie-vagrant-amd64-official-20250917-1 CLOUD_BUILD_OUTPUT_DIR=/home/rajudev/dev/salsa/michael/debian-vagrant-images CLOUD_RELEASE_ID=vagrant CLOUD_RELEASE_VERSION=20250917-1 fai-diskimage --verbose --hostname debian --class DEBIAN,CLOUD,TRIXIE,VAGRANT,AMD64,LINUX_IMAGE_BASE,GRUB_PC,LAST --size 100G --cspace /home/rajudev/dev/salsa/michael/debian-vagrant-images/src/debian_cloud_images/build/fai_config debian-trixie-vagrant-amd64-official-20250917-1.raw
..... continued
Although we can now build the images, we just don&apost see an option for it in the help text, not even for bookworm. Just the text in Makefile is outdated, but I can build and trixie Vagrant box now. Thanks to Michael for the fix.

15 September 2025

Sven Hoexter: Google Cloud: When the Load Balancer Frontend Hands you an F

If someone hands you an IP:Port of a Google Cloud load balancer, and tells you to connect there with TLS, but all you receive in return is an F (and a few other bytes with none printable characters) on running openssl s_client -connect ..., you might be missing SNI (server name indication). Sadly the other side was not transparent enough to explain in detail which exact type of Google Cloud load balancer they used, but the conversation got more detailed and up to a working TLS connection when the missing -servername foobar.host.name was added. I could not find any sort of official documentation on the responses of the GFE (the frontend part) when TLS parameters do not match the expectations. Also you won't have anything in the logs, because logging at Google Cloud is a backend function, and as long as your requests do not reach the backend, there are no logs. That makes it rather unpleasant to debug such cases, when one end says "I do not see anything in the logs", and the other one says "you reject my connection and just reply F".

14 September 2025

Ian Jackson: tag2upload in the first month of forky

tl;dr: tag2upload (beta) is going well so far, and is already handling around one in 13 uploads to Debian. Introduction and some stats We announced tag2upload s open beta in mid-July. That was in the middle of the the freeze for trixie, so usage was fairly light until the forky floodgates opened. Since then the service has successfully performed 637 uploads, of which 420 were in the last 32 days. That s an average of about 13 per day. For comparison, during the first half of September up to today there have been 2475 uploads to unstable. That s about 176/day. So, tag2upload is already handling around 7.5% of uploads. This is very gratifying for a service which is advertised as still being in beta! Sean and I are very pleased both with the uptake, and with the way the system has been performing. Recent UI/UX improvements During this open beta period we have been hard at work. We have made many improvements to the user experience. Current git-debpush in forky, or trixie-backports, is much better at detecting various problems ahead of time. When uploads do fail on the service the emailed error reports are now more informative. For example, anomalies involving orig tarballs, which by definition can t be detected locally (since one point of tag2upload is not to have tarballs locally) now generally result in failure reports containing a diffstat, and instructions for a local repro. Why we are still in beta There are a few outstanding work items that we currently want to complete before we declare the end of the beta. Retrying on Salsa-side failures The biggest of these is that the service should be able to retry when Salsa fails. Sadly, Salsa isn t wholly reliable, and right now if it breaks when the service is trying to handle your tag, your upload can fail. We think most of these failures could be avoided. Implementing retries is a fairly substantial task, but doesn t pose any fundamental difficulties. We re working on this right now. Other notable ongoing work We want to support pristine-tar, so that pristine-tar users can do a new upstream release. Andrea Pappacoda is working on that with us. See #1106071. (Note that we would generally recommend against use of pristine-tar within Debian. But we want to support it.) We have been having conversations with Debusine folks about what integration between tag2upload and Debusine would look like. We re making some progress there, but a lot is still up in the air. We are considering how best to provide tag2upload pre-checks as part of Salsa CI. There are several problems detected by the tag2upload service that could be detected by Salsa CI too, but which can t be detected by git-debpush. Common problems We ve been monitoring the service and until very recently we have investigated every service-side failure, to understand the root causes. This has given us insight into the kinds of things our users want, and the kinds of packaging and git practices that are common. We ve been able to improve the system s handling of various anomalies and also improved the documentation. Right now our failure rate is still rather high, at around 7%. Partly this is because people are trying out the system on packages that haven t ever seen git tooling with such a level of rigour. There are two classes of problem that are responsible for the vast majority of the failures that we re still seeing: Reuse of version numbers, and attempts to re-tag tag2upload, like git (and like dgit), hates it when you reuse a version number, or try to pretend that a (perhaps busted) release never happened. git tags aren t namespaced, and tend to spread about promiscuously. So replacing a signed git tag, with a different tag of the same name, is a bad idea. More generally, reusing the same version number for a different (signed!) package is poor practice. Likewise, it s usually a bad idea to remove changelog entries for versions which were actually released, just because they were later deemed improper. We understand that many Debian contributors have gotten used to this kind of thing. Indeed, tools like dcut encourage it. It does allow you to make things neat-looking, even if you ve made mistakes - but really it does so by covering up those mistakes! The bottom line is that tag2upload can t support such history-rewriting. If you discover a mistake after you ve signed the tag, please just burn the version number and add a new changelog stanza. One bonus of tag2upload s approach is that it will discover if you are accidentally overwriting an NMU, and report that as an error. Discrepancies between git and orig tarballs tag2upload promises that the source package that it generates corresponds precisely to the git tree you tag and sign. Orig tarballs make this complicated. They aren t present on your laptop when you git-debpush. When you re not uploading a new upstream version, the tag2upload service reuses existing orig tarballs from the archive. If your git and the archive s orig don t agree, the tag2upload service will report an error, rather than upload a package with contents that differ from your git tag. With the most common Debian workflows, everything is fine: If you base everything on upstream git, and make your orig tarballs with git archive (or git deborig), your orig tarballs are the same as the git, by construction. We recommend usually ignoring upstream tarballs: most upstreams work in git, and their tarballs can contain weirdness that we don t want. (At worst, the tarball can contain an attack that isn t visible in git, as with xz!) Alternatively, if you use gbp import-orig, the differences (including an attack like Jia Tan s) are imported into git for you. Then, once again, your git and the orig tarball will correspond. But there are other workflows where this correspondence may not hold. Those workflows are hazardous, because the thing you re probably working with locally for your routine development is the git view. Then, when you upload, your work is transplanted onto the orig tarball, which might be quite different - so what you upload isn t what you ve been working on! This situation is detected by tag2upload, precisely because tag2upload checks that it s keeping its promise: the source package is identical to the git view. (dgit push makes the same promise.) Get involved Of course the easiest way to get involved is to start using tag2upload. We would love to have more contributors. There are some easy tasks to get started with, in bugs we ve tagged newcomer mostly UX improvements such as detecting certain problems earlier, in git-debpush. More substantially, we are looking for help with sbuild: we d like it to be able to work directly from git, rather than needing to build source packages: #868527.

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Dirk Eddelbuettel: RcppSimdJson 0.1.14 on CRAN: New Upstream Major

A brand new release 0.1.14 of the RcppSimdJson package is now on CRAN. RcppSimdJson wraps the fantastic and genuinely impressive simdjson library by Daniel Lemire and collaborators. Via very clever algorithmic engineering to obtain largely branch-free code, coupled with modern C++ and newer compiler instructions, it results in parsing gigabytes of JSON parsed per second which is quite mindboggling. The best-case performance is faster than CPU speed as use of parallel SIMD instructions and careful branch avoidance can lead to less than one cpu cycle per byte parsed; see the video of the talk by Daniel Lemire at QCon. This version includes the new major upstream release 4.0.0 with major new features including a builder for creating JSON from the C++ side objects. This is something a little orthogonal to the standard R usage of the package to parse and load JSON data but could still be of interest to some. The short NEWS entry for this release follows.

Changes in version 0.1.14 (2025-09-13)
  • simdjson was upgraded to version 4.0.0 (Dirk in #96
  • Continuous integration now relies a token for codecov.io

Courtesy of my CRANberries, there is also a diffstat report for this release. For questions, suggestions, or issues please use the issue tracker at the GitHub repo.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. If you like this or other open-source work I do, you can now sponsor me at GitHub.

Otto Kek l inen: Zero-configuration TLS and password management best practices in MariaDB 11.8

Featured image of post Zero-configuration TLS and password management best practices in MariaDB 11.8Locking down database access is probably the single most important thing for a system administrator or software developer to prevent their application from leaking its data. As MariaDB 11.8 is the first long-term supported version with a few new key security features, let s recap what the most important things are every DBA should know about MariaDB in 2025. Back in the old days, MySQL administrators had a habit of running the clumsy mysql-secure-installation script, but it has long been obsolete. A modern MariaDB database server is already secure by default and locked down out of the box, and no such extra scripts are needed. On the contrary, the database administrator is expected to open up access to MariaDB according to the specific needs of each server. Therefore, it is important that the DBA can understand and correctly configure three things:
  1. Separate application-specific users with granular permissions allowing only necessary access and no more.
  2. Distributing and storing passwords and credentials securely
  3. Ensuring all remote connections are properly encrypted
For holistic security, one should also consider proper auditing, logging, backups, regular security updates and more, but in this post we will focus only on the above aspects related to securing database access.

How encrypting database connections with TLS differs from web server HTTP(S) Even though MariaDB (and other databases) use the same SSL/TLS protocol for encrypting remote connections as web servers and HTTPS, the way it is implemented is significantly different, and the different security assumptions are important for a database administrator to grasp. Firstly, most HTTP requests to a web server are unauthenticated, meaning the web server serves public web pages and does not require users to log in. Traditionally, when a user logs in over a HTTP connection, the username and password were transmitted in plaintext as a HTTP POST request. Modern TLS, which was previously called SSL, does not change how HTTP works but simply encapsulates it. When using HTTPS, a web browser and a web server will start an encrypted TLS connection as the very first thing, and only once established, do they send HTTP requests and responses inside it. There are no passwords or other shared secrets needed to form the TLS connection. Instead, the web server relies on a trusted third party, a Certificate Authority (CA), to vet that the TLS certificate offered by the web server can be trusted by the web browser. For a database server like MariaDB, the situation is quite different. All users need to first authenticate and log in to the server before getting being allowed to run any SQL and getting any data out of the server. The database server and client programs have built-in authentication methods, and passwords are not, and have never been, sent in plaintext. Over the years, MySQL and its successor, MariaDB, have had multiple password authentication methods: the original SHA-1-based hashing, later double SHA-1-based mysql_native_password, followed by sha256_password and caching_sha256_password in MySQL and ed25519 in MariaDB. The MariaDB.org blog post by Sergei Golubchik recaps the history of these well. Even though most modern MariaDB installations should be using TLS to encrypt all remote connections in 2025, having the authentication method be as secure as possible still matters, because authentication is done before the TLS connection is fully established. To further harden the authentication agains man-in-the-middle attacks, a new password the authentication method PARSEC was introduced in MariaDB 11.8, which builds upon the previous ed25519 public-key-based verification (similar to how modern SSH does), and also combines key derivation with PBKDF2 with hash functions (SHA512,SHA256) and a high iteration count. At first it may seem like a disadvantage to not wrap all connections in a TLS tunnel like HTTPS does, but actually not having the authentication done in a MitM resistant way regardless of the connection encryption status allows a clever extra capability that is now available in MariaDB: as the database server and client already have a shared secret that is being used by the server to authenticate the user, it can also be used by the client to validate the server s TLS certificate and no third parties like CAs or root certificates are needed. MariaDB 11.8 was the first LTS version to ship with this capability for zero-configuration TLS. Note that the zero-configuration TLS also works on older password authentication methods and does not require users to have PARSEC enabled. As PARSEC is not yet the default authentication method in MariaDB, it is recommended to enable it in installations that use zero-configuration TLS encryption to maximize the security of the TLS certificate validation.

Why the root user in MariaDB has no password and how it makes the database more secure Relying on passwords for security is problematic, as there is always a risk that they could leak, and a malicious user could access the system using the leaked password. It is unfortunately far too common for database passwords to be stored in plaintext in configuration files that are accidentally committed into version control and published on GitHub and similar platforms. Every application or administrative password that exists should be tracked to ensure only people who need it know it, and rotated at regular intervals to ensure old employees etc won t be able to use old passwords. This password management is complex and error-prone. Replacing passwords with other authentication methods is always advisable when possible. On a database server, whoever installed the database by running e.g. apt install mariadb-server, and configured it with e.g. nano /etc/mysql/mariadb.cnf, already has full root access to the operating system, and asking them for a password to access the MariaDB database shell is moot, since they could circumvent any checks by directly accessing the files on the system anyway. Therefore, MariaDB, since version 10.4 stopped requiring the root user to enter a password when connecting locally, and instead checks using socket authentication whether the user is the operating-system root user or equivalent (e.g. running sudo). This is an elegant way to get rid of a password that was actually unnecessary to begin with. As there is no root password anymore, the risk of an external user accessing the database as root with a leaked password is fully eliminated. Note that socket authentication only works for local connections on the same server. If you want to access a MariaDB server remotely as the root user, you would need to configure a password for it first. This is not generally recommended, as explained in the next section.

Create separate database users for normal use and keep root for administrative use only Out of the box a MariaDB installation is already secure by default, and only the local root user can connect to it. This account is intended for administrative use only, and for regular daily use you should create separate database users with access limited to the databases they need and the permissions required. The most typical commands needed to create a new database for an app and a user the app can use to connect to the database would be the following:
sql 
CREATE DATABASE app_db;
CREATE USER 'app_user'@'%' IDENTIFIED BY 'your_secure_password';
GRANT ALL PRIVILEGES ON app_db.* TO 'app_user'@'%';
FLUSH PRIVILEGES;
Alternatively, if you want to use the parsec authentication method, run this to create the user:
sql 
CREATE OR REPLACE USER 'app_user'@'%'
 IDENTIFIED VIA parsec
 USING PASSWORD('your_secure_password');
Note that the plugin auth_parsec is not enabled by default. If you see the error message ERROR 1524 (HY000): Plugin 'parsec' is not loaded fix this by running INSTALL SONAME 'auth_parsec';. In the CREATE USER statements, the @'%' means that the user is allowed to connect from any host. This needs to be defined, as MariaDB always checks permissions based on both the username and the remote IP address or hostname of the user, combined with the authentication method. Note that it is possible to have multiple user@remote combinations, and they can have different authentication methods. A user could, for example, be allowed to log in locally using the socket authentication and over the network using a password. If you are running a custom application and you know exactly what permissions are sufficient for the database users, replace the ALL PRIVILEGES with a subset of privileges listed in the MariaDB documentation. For new permissions to take effect, restart the database or run FLUSH PRIVILEGES.

Allow MariaDB to accept remote connections and enforce TLS Using the above 'app_user'@'%' is not enough on its own to allow remote connections to MariaDB. The MariaDB server also needs to be configured to listen on a network interface to accept remote connections. As MariaDB is secure by default, it only accepts connections from localhost until the administrator updates its configuration. On a typical Debian/Ubuntu system, the recommended way is to drop a new custom config in e.g. /etc/mysql/mariadb.conf.d/99-server-customizations.cnf, with the contents: 
[mariadbd]
# Listen for connections from anywhere
bind-address = 0.0.0.0
# Only allow TLS encrypted connections
require-secure-transport = on
For settings to take effect, restart the server with systemctl restart mariadb. After this, the server will accept connections on any network interface. If the system is using a firewall, the port 3306 would additionally need to be allow-listed. To confirm that the settings took effect, run e.g. mariadb -e "SHOW VARIABLES LIKE 'bind_address';" , which should now show 0.0.0.0. When allowing remote connections, it is important to also always define require-secure-transport = on to enforce that only TLS-encrypted connections are allowed. If the server is running MariaDB 11.8 and the clients are also MariaDB 11.8 or newer, no additional configuration is needed thanks to MariaDB automatically providing TLS certificates and appropriate certificate validation in recent versions. On older long-term-supported versions of the MariaDB server one would have had to manually create the certificates and configure the ssl_key, ssl_cert and ssl_ca values on the server, and distribute the certificate to the clients as well, which was cumbersome, so good it is not required anymore. In MariaDB 11.8 the only additional related config that might still be worth setting is tls_version = TLSv1.3 to ensure only the latest TLS protocol version is used. Finally, test connections to ensure they work and to confirm that TLS is used by running e.g.:
shell 
mariadb --user=app_user --password=your_secure_password \
 --host=192.168.1.66 -e '\s'
The result should show something along: 
--------------
mariadb from 11.8.3-MariaDB, client 15.2 for debian-linux-gnu (x86_64)
...
Current user: app_user@192.168.1.66
SSL: Cipher in use is TLS_AES_256_GCM_SHA384, cert is OK
...
If running a Debian/Ubuntu system, see the bundled README with zcat /usr/share/doc/mariadb-server/README.Debian.gz to read more configuration tips.

Should TLS encryption be used also on internal networks? If a database server and app are running on the same private network, the chances that the connection gets eavesdropped on or man-in-the-middle attacked by a malicious user are low. However, it is not zero, and if it happens, it can be difficult to detect or prove that it didn t happen. The benefit of using end-to-end encryption is that both the database server and the client can validate the certificates and keys used, log it, and later have logs audited to prove that connections were indeed encrypted and show how they were encrypted. If all the computers on an internal network already have centralized user account management and centralized log collection that includes all database sessions, reusing existing SSH connections, SOCKS proxies, dedicated HTTPS tunnels, point-to-point VPNs, or similar solutions might also be a practical option. Note that the zero-configuration TLS only works with password validation methods. This means that systems configured to use PAM or Kerberos/GSSAPI can t use it, but again those systems are typically part of a centrally configured network anyway and are likely to have certificate authorities and key distribution or network encryption facilities already set up. In a typical software app stac however, the simplest solution is often the best and I recommend DBAs use the end-to-end TLS encryption in MariaDB 11.8 in most cases. Hopefully with these tips you can enjoy having your MariaDB deployments both simpler and more secure than before!

12 September 2025

Christoph Berg: The Cost of TDE and Checksums in PGEE

It's been a while since the last performance check of Transparent Data Encryption (TDE) in Cybertec's PGEE distribution - that was in 2016. Of course, the question is still interesting, so I did some benchmarks. Since the difference is really small between running without any extras, with data checksums turned on, and with both encryption and checksums turned on, we need to pick a configuration that will stress-test these features the most. So in the spirit of making PostgreSQL deliberately run slow, I went with only 1MB of shared_buffers with a pgbench workload of scale factor 50. The 770MB of database size will easily fit into RAM. However, having such a small buffer cache setting will cause a lot of cache misses with pages re-read from the OS disk cache, checksums checked, and the page decrypted again. To further increase the effect, I ran pgbench --skip-some-updates so the smaller, in-cache-anyway pgbench tables are not touched. Overall, this yields a pretty consistent buffer cache hit rate of only 82.8%. Here are the PGEE 17.6 tps (transactions per second) numbers averaged over a few 1-minute 3-client pgbench runs for different combinations of data checksums on/off, TDE off, and the various supported key bit lengths:
no checksums data checksums
no TDE 2455,6 100,00 % 2449,7 99,76 %
128 bits 2440,9 99,40 % 2443,3 99,50 %
192 bits 2439,6 99,35 % 2446,1 99,61 %
256 bits 2450,3 99,78 % 2443,1 99,49 %
There is a lot of noise in the individual runtimes before averaging, so the numbers must be viewed with some care (192-bit TDE is certainly not faster with checksums than without), but if we dare to interpret these tiny differences, we can conclude the following: Any workload with a better shared_buffers cache hit rate would see a lower penalty of enabling checksums and TDE than that. The post The Cost of TDE and Checksums in PGEE appeared first on CYBERTEC PostgreSQL Services & Support.

Freexian Collaborators: Using JavaScript in Debusine without depending on JavaScript (by Enrico Zini)

Debusine is a tool designed for Debian developers and Operating System developers in general. This posts describes our approach to the use of JavaScript, and some practical designs we came up with to integrate it with Django with minimal effort.

Debusine web UI and JavaScript Debusine currently has 3 user interfaces: a client on the command line, a RESTful API, and a Django-based Web UI. Debusine s web UI is a tool to interact with the system, and we want to spend most of our efforts in creating a system that works and works well, rather than chasing the latest and hippest of the frontend frameworks for the web. Also, Debian as a community has an aversion to having parts of the JavaScript ecosystem in the critical path of its core infrastructure, and in our professional experience this aversion is not at all unreasonable. This leads to having some interesting requirements for the web UI, that (rather surprisingly, one would think) one doesn t usually find advertised in many projects:
  • Straightforward to create and maintain.
  • Well integrated with Django.
  • Easy to package in Debian, with as little vendoring as possible, which helps mitigate supply chain attacks
  • Usable without JavaScript whenever possible, for progressive enhancement rather than core functionality.
The idea is to avoid growing the technical complexity and requirements of the web UI, both server-side and client-side, for functionality that is not needed for this kind of project, with tools that do not fit well in our ecosystem. Also, to limit the complexity of the JavaScript portions that we do develop, we choose to limit our JavaScript browser supports to the main browser versions packaged in Debian Stable, plus recent oldstable. This makes JavaScript easier to write and maintain, and it also makes it less needed, as modern HTML plus modern CSS interfaces can go a long way with less scripting interventions. We recently encoded JavaScript practices and tradeoffs in a JavaScript Practices chapter of Debusine s documentation.

How we use JavaScript From the start we built the UI using Bootstrap, which helps in having responsive layouts that can also work on mobile devices. When we started having large select fields, we introduced Select2 to make interaction more efficient, and which degrades gracefully to working HTML. Both Bootstrap and Select2 are packaged in Debian. Form validation is done server-side by Django, and we do not reimplement it client-side in JavaScript, as we prefer the extra round trip through a form submission to the risk of mismatches between the two validations. In those cases where a UI task is not at all possible without JavaScript, we can make its support mandatory as long as the same goal can be otherwise achieved using the debusine client command.

Django messages as Bootstrap toasts Django has a Messages framework that allows different parts of a view to push messages to the user, and it is useful to signal things like a successful form submission, or warnings on unexpected conditions. Django messages integrate well with Bootstrap toasts, which use a recognisable notification language, are nicely dismissible and do not invade the rest of the page layout. Since toasts require JavaScript to work, we added graceful degradation. to Bootstrap alerts Doing so was surprisingly simple: we handle the toasts as usual, and also render the plain alerts inside a <noscript> tag. This is precisely the intended usage of the <noscript> tag, and it works perfectly: toasts are displayed by JavaScript when it s available, or rendered as alerts when not. The resulting Django template is something like this: 
<div aria-live="polite" aria-atomic="true" class="position-relative">
    <div class="toast-container position-absolute top-0 end-0 p-3">
     % for message in messages % 
        <div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
            <div class="toast-header">
                <strong class="me-auto">  message.level_tag capfirst  </strong>
                <button type="button"
                        class="btn-close"
                        data-bs-dismiss="toast"
                        aria-label="Close"></button>
            </div>
            <div class="toast-body">  message  </div>
        </div>
     % endfor % 
    </div>
</div>
<!--   -->
 % if messages % 
<noscript>
     % for message in messages % 
        <div class="alert alert-primary" role="alert">
              message  
        </div>
     % endfor % 
</noscript>
 % endif %
We have a webpage to test the result.

JavaScript incremental improvement of formsets Debusine is built around workspaces, which are, among other things, containers for resources. Workspaces can inherit from other workspaces, which act as fallback lookups for resources. This allows, for example, to maintain an experimental package to be built on Debian Unstable, without the need to copy the whole Debian Unstable workspace. A workspace can inherit from multiple others, which are looked up in order. When adding UI to configure workspace inheritance, we faced the issue that plain HTML forms do not have a convenient way to perform data entry of an ordered list. We initially built the data entry around Django formsets, which support ordering using an extra integer input field to enter the ordering position. This works, and it s good as a fallback, but we wanted something more appropriate, like dragging and dropping items to reorder them, as the main method of interaction. Our final approach renders the plain formset inside a <noscript> tag, and the JavaScript widget inside a display: none element, which is later shown by JavaScript code. As the workspace inheritance is edited, JavaScript serializes its state into <form type='hidden'> fields that match the structure used by the formset, so that when the form is submitted, the view performs validation and updates the server state as usual without any extra maintenance burden. Serializing state as hidden form fields looks a bit vintage, but it is an effective way of preserving the established data entry protocol between the server and the browser, allowing us to do incremental improvement of the UI while minimizing the maintenance effort.

More to come Debusine is now gaining significant adoption and is still under active development, with new features like personal archives coming soon. This will likely mean more user stories for the UI, so this is a design space that we are going to explore again and again in the coming future. Meanwhile, you can try out Debusine on debusine.debian.net, and follow its development on salsa.debian.org!

11 September 2025

John Goerzen: Performant Full-Disk Encryption on a Raspberry Pi, but Foiled by Twisty UARTs

In my post yesterday, ARM is great, ARM is terrible (and so is RISC-V), I described my desire to find ARM hardware with AES instructions to support full-disk encryption, and the poor state of the OS ecosystem around the newer ARM boards. I was anticipating buying either a newer ARM SBC or an x86 mini PC of some sort. More-efficient AES alternatives Always one to think, what if I didn t have to actually buy something , I decided to research whether it was possible to use encryption algorithms that are more performant on the Raspberry Pi 4 I already have. The answer was yes. From cryptsetup benchmark: 
root@mccoy:~# cryptsetup benchmark --cipher=xchacha12,aes-adiantum-plain64 
# Tests are approximate using memory only (no storage IO).
#            Algorithm         Key        Encryption        Decryption
xchacha12,aes-adiantum        256b       159.7 MiB/s       160.0 MiB/s
xchacha20,aes-adiantum        256b       116.7 MiB/s       169.1 MiB/s
    aes-xts                   256b        52.5 MiB/s        52.6 MiB/s
With best-case reads from my SD card at 45MB/s (with dd if=/dev/mmcblk0 of=/dev/null bs=1048576 status=progress), either of the ChaCha-based algorithms will be fast enough. Great, I thought. Now I can just solve this problem without spending a dollar. But not so fast. Serial terminals vs. serial consoles My primary use case for this device is to drive my actual old DEC vt510 terminal. I have long been able to do that by running a getty for my FTDI-based USB-to-serial converter on /dev/ttyUSB0. This gets me a login prompt, and I can do whatever I need from there. This does not get me a serial console, however. The serial console would show kernel messages and could be used to interact with the pre-multiuser stages of the system that is, everything before the loging prompt. You can use it to access an emergency shell for repair, etc. Although I have long booted that kernel with console=tty0 console=ttyUSB0,57600, the serial console has never worked but I d never bothered investigating because the text terminal was sufficient. You might be seeing where this is going: to have root on an encrypted LUKS volume, you have to enter the decryption password in the pre-multiuser environment (which happens to be on the initramfs). So I started looking. First, I extracted the initrd with cpio and noticed that the ftdi_sio and usbserial modules weren t present. Added them to /etc/initramfs-tools/modules and rebooted; no better. So I found the kernel s serial console guide, which explicitly notes To use a serial port as console you need to compile the support into your kernel . Well, I have no desire to custom-build a kernel on a Raspberry Pi with MicroSD storage every time a new kernel comes out. I thought well I don t stricly need the kernel to know about the console on /dev/ttyUSB0 for this; I just need the password prompt which comes from userspace to know about it. So I looked at the initramfs code, and wouldn t you know it, it uses /dev/console. Looking at /proc/consoles on that system, indeed it doesn t show ttyUSB0. So even though it is possible to load the USB serial driver in the initramfs, there is no way to make the initramfs use it, because it only uses whatever the kernel recognizes as a console, and the kernel won t recognize this. So there is no way to use a USB-to-serial adapter to enter a password for an encrypted root filesystem. Drat. The on-board UARTs? I can hear you know: The Pi already has on-board serial support! Why not use that? Ah yes, the reason I don t want to use that is because it is difficult to use that, particularly if you want to have RTS/CTS hardware flow control (or DTR/DSR on these old terminals, but that s another story, and I built a custom cable to map it to RTS/CTS anyhow). Since you asked, I ll take you down this unpleasant path. The GPIO typically has only 2 pins for serial communication: 8 and 10, for TX and RX, respectively. But dive in and you get into a confusing maze of UARTs. The mini UART , the one we are mostly familiar with on the Pi, does not support hardware flow control. The PL011 does. So the natural question is: how do we switch to the PL011, and what pins does it use? Great questions, and the answer is undocumented, at least for the Pi 4. According to that page, for the Pi 4, the primary UART is UART1, UART1 is the mini UART, the secondary UART is not normally present on the GPIO connector and might be used by Bluetooth anyway, and there is no documented pin for RTS/CTS anyhow. (Let alone some of the other lines modems use) There are supposed to be /dev/ttyAMA* devices, but I don t have those. There s an enable_uart kernel parameter, which does things like stop the mini UART from changing baud rates every time the VPU changes clock frequency (I am not making this up!), but doesn t seem to control the PL011 UART selection. This page has a program to do it, and map some GPIO pins to RTS/CTS, in theory. Even if you get all that working, you still have the problem that the Pi UARTs (all of them of every type) is 3.3V and RS-232 is 5V, so unless you get a converter, you will fry your Pi the moment you connect it to something useful. So, you re probably looking at some soldering and such just to build a cable that will work with an iffy stack. So, I could probably make it work given enough time, but I don t have that time to spare working with weird Pi serial problems, so I have always used USB converters when I need serial from a Pi. Conclusion I bought a fanless x86 micro PC with a N100 chip and all the ports I might want: a couple of DB-9 serial ports, some Ethernet ports, HDMI and VGA ports, and built-in wifi. Done.

Freexian Collaborators: Monthly report about Debian Long Term Support, August 2025 (by Roberto C. S nchez)

Like each month, have a look at the work funded by Freexian s Debian LTS offering.

Debian LTS contributors In August, 21 contributors have been paid to work on Debian LTS, their reports are available:
  • Abhijith PA did 10.0h (out of 0.0h assigned and 14.0h from previous period), thus carrying over 4.0h to the next month.
  • Andrej Shadura did 12.0h (out of 9.0h assigned and 3.0h from previous period).
  • Bastien Roucari s did 20.0h (out of 19.75h assigned and 0.25h from previous period).
  • Ben Hutchings did 22.75h (out of 16.5h assigned and 6.25h from previous period).
  • Carlos Henrique Lima Melara did 10.0h (out of 10.0h assigned).
  • Chris Lamb did 18.0h (out of 18.0h assigned).
  • Daniel Leidert did 23.25h (out of 23.25h assigned).
  • Emilio Pozuelo Monfort did 23.25h (out of 23.25h assigned).
  • Guilhem Moulin did 15.0h (out of 15.0h assigned).
  • Jochen Sprickerhof did 11.0h (out of 6.0h assigned and 16.75h from previous period), thus carrying over 11.75h to the next month.
  • Lee Garrett did 16.25h (out of 0.0h assigned and 16.25h from previous period).
  • Lucas Kanashiro did 20.0h (out of 1.25h assigned and 18.75h from previous period).
  • Markus Koschany did 5.0h (out of 13.0h assigned and 9.75h from previous period), thus carrying over 17.75h to the next month.
  • Paride Legovini did 8.0h (out of 0.0h assigned and 8.0h from previous period).
  • Roberto C. S nchez did 7.5h (out of 11.75h assigned and 11.0h from previous period), thus carrying over 15.25h to the next month.
  • Santiago Ruano Rinc n did 13.5h (out of 7.25h assigned and 7.75h from previous period), thus carrying over 1.5h to the next month.
  • Stefano Rivera did 0.5h (out of 0.0h assigned and 3.0h from previous period), thus carrying over 2.5h to the next month.
  • Sylvain Beucler did 10.0h (out of 23.25h assigned), thus carrying over 13.25h to the next month.
  • Thorsten Alteholz did 22.75h (out of 22.75h assigned).
  • Tobias Frost did 4.0h (out of 0.0h assigned and 12.0h from previous period), thus carrying over 8.0h to the next month.
  • Utkarsh Gupta did 16.0h (out of 22.75h assigned), thus carrying over 6.75h to the next month.

Evolution of the situation In August, we released 27 DLAs. The month of August marked the release of Debian 13 (codename trixie ). This is worth noting because it brought with it the return of the customary fast development pace of Debian unstable, which included several contributions from LTS Team members. More on that below. Of the many security updates which were published (and a few non-security updates as well), some notable ones are highlighted here.
  • Notable security updates:
    • gnutls28 prepared by Adrian Bunk, fixes several potential denial of service vulnerabilities
    • apache2, prepared by Bastien Roucari s, fixes several vulnerabilities including a potential denial of service and SSL/TLS-related access control
    • mbedtls (original update, regression update) prepared by Andrej Shadura, fixes several potential denial of service and information disclosure vulnerabilities
    • openjdk-17, prepared by Emilio Pozuelo Monfort, fixes several vulnerabilities which could result in denial of service, information disclosure or weakened TLS connections
  • Notable non-security updates:
    • distro-info-data, prepared by Stefano Rivera, adds information concerning future Debian and Ubuntu releases
    • ca-certificates-java, prepared by Bastien Roucari s, fixes some bugs which could disrupt future updates
The LTS Team continues to welcome the collaboration of maintainers from across the Debian community. The contributions of maintainers from outside the LTS Team include: postgresql-13 (Christoph Berg), sope (Jordi Mallach), thunderbird (Carsten Schoenert), and iperf3 (Roberto Lumbreras). Finally, LTS Team members also contributed updates of the following packages:
  • redis (to stable), prepared by Chris Lamb
  • firebird3.0 (to oldstable and stable), prepared by Adrian Bunk
  • node-tmp (to oldstable, stable, and unstable), prepared by Adrian Bunk
  • openjpeg2 (to oldstable, stable, and unstable), prepared by Adrian Bunk
  • apache2 (to oldstable), prepared by Bastien Roucari s
  • unbound (to oldstable), prepared by Guilhem Moulin
  • luajit (to oldstable), prepared by Guilhem Moulin
  • golang-github-gin-contrib-cors (to oldstable and stable), prepared by Thorsten Alteholz
  • libcoap3 (to stable), prepared by Thorsten Alteholz
  • libcommons-lang-java and libcommons-lang3-java (both to unstable), prepared by Daniel Leidert
  • python-flask-cors (to oldstable), prepared by Daniel Leidert
The LTS Team would especially like to thank our many longtime friends and sponsors for their support and collaboration.

Thanks to our sponsors Sponsors that joined recently are in bold.

9 September 2025

Dirk Eddelbuettel: RcppSMC 0.2.9 on CRAN: Maintenance

Release 0.2.9 of our RcppSMC package arrived at CRAN today. RcppSMC provides Rcpp-based bindings to R for the Sequential Monte Carlo Template Classes (SMCTC) by Adam Johansen described in his JSS article. Sequential Monte Carlo is also referred to as Particle Filter in some contexts. The package now also features the Google Summer of Code work by Leah South in 2017, and by Ilya Zarubin in 2021. This release is again entirely internal. It updates the code for the just-released RcppArmadillo 15.0.2-1, in particular opts into Armadillo 15.0.2. And it makes one small tweak to the continuous integration setup switching to the r-ci action. The release is summarized below.

Changes in RcppSMC version 0.2.9 (2025-09-09)
  • Adjust to RcppArmadillo 15.0.* by setting ARMA_USE_CURRENT and updating two expressions from deprecated code
  • Rely on r-ci GitHub Action which includes the bootstrap step

Courtesy of my CRANberries, there is also a diffstat report detailing changes. More information is on the RcppSMC page and the repo. Issues and bugreports should go to the GitHub issue tracker.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. If you like this or other open-source work I do, you can sponsor me at GitHub.

John Goerzen: btrfs on a Raspberry Pi

I m something of a filesystem geek, I guess. I first wrote about ZFS on Linux 14 years ago, and even before I used ZFS, I had used ext2/3/4, jfs, reiserfs, xfs, and no doubt some others. I ve also used btrfs. I last posted about it in 2014, when I noted it has some advantages over ZFS, but also some drawbacks, including a lot of kernel panics. Since that comparison, ZFS has gained trim support and btrfs has stabilized. The btrfs status page gives you an accurate idea of what is good to use on btrfs. Background: Moving towards ZFS and btrfs I have been trying to move everything away from ext4 and onto either ZFS or btrfs. There are generally several reasons for that:
  1. The checksums for every block help detect potential silent data corruption
  2. Instant snapshots make consistent backups of live systems a lot easier, and without the hassle and wasted space of LVM snapshots
  3. Transparent compression and dedup can save a lot of space in storage-constrained environments
For any machine with at least 32GB of RAM (plus my backup server, which has only 8GB), I run ZFS. While it lacks some of the flexibility of btrfs, it has polish. zfs list -o space shows a useful space accounting. zvols can be behind VMs. With my project simplesnap, I can easily send hourly backups with ZFS, and I choose to send them over NNCP in most cases. I have a few VMs in the cloud (running Debian, of course) that I use to host things like this blog, my website, my gopher site, the quux NNCP public relay, and various other things. In these environments, storage space can be expensive. For that matter, so can RAM. ZFS is RAM-hungry, so that rules out ZFS. I ve been running btrfs in those environments for a few years now, and it s worked out well. I do async dedup, lzo or zstd compression depending on the needs, and the occasional balance and defrag. Filesystems on the Raspberry Pi I run Debian trixie on all my Raspberry Pis; not Raspbian or Raspberry Pi OS for a number of reasons. My 8-yr-old uses a Raspberry Pi 400 as her primary computer and loves it! She doesn t do web browsing, but plays Tuxpaint, some old DOS games like Math Blaster via dosbox, and uses Thunderbird for a locked-down email account. But it was SLOW. Just really, glacially, slow, especially for Thunderbird. My first step to address that was to get a faster MicroSD card to hold the OS. That was a dramatic improvement. It s still slow, but a lot faster. Then, I thought, maybe I could use btrfs with LZO compression to reduce the amount of I/O and speed things up further? Analysis showed things were mostly slow due to I/O, not CPU, constraints. The conversion Rather than use the btrfs in-place conversion from ext4, I opted to dar it up (like tar), run mkfs.btrfs on the SD card, then unpack the archive back onto it. Easy enough, right? Well, not so fast. The MicroSD card is 128GB, and the entire filesystem is 6.2GB. But after unpacking 100MB onto it, I got an out of space error. btrfs has this notion of block groups. By default, each block group is dedicated to either data or metadata. btrfs fi df and btrfs fi usage will show you details about the block groups. btrfs allocates block groups greedily (the ssd_spread mount option I use may have exacerbated this). What happened was it allocated almost the entire drive to data block groups, trying to spread the data across it. It so happened that dar archived some larger files first (maybe /boot), so btrfs was allocating data and metadata blockgroups assuming few large files. But then it started unpacking one of the directories in /usr with lots of small files (maybe /usr/share/locale). It quickly filled up the metadata block group, and since the entire SD card had been allocated to different block groups, I got ENOSPC. Deleting a few files and running btrfs balance resolved it; now it allocated 1GB to metadata, which was plenty. I re-ran the dar extract and now everything was fine. See more details on btrfs balance and block groups. This was the only btrfs problem I encountered. Benchmarks I timed two things prior to switching to btrfs: how long it takes to boot (measured from the moment I turn on the power until the moment the XFCE login box is displayed), and how long it takes to start Thunderbird. After switching to btrfs with LZO compression, somewhat to my surprise, both measures were exactly the same! Why might this be? It turns out that SD cards are understood to be pathologically bad with random read performance. Boot and Thunderbird both are likely doing a lot of small random reads, not large streaming reads. Therefore, it may be that even though I have reduced the total I/O needed, the impact is unsubstantial because the real bottleneck is the seeks across the disk. Still, I gain the better backup support and silent data corruption prevention, so I kept btrfs. SSD mount options and MicroSD endurance btrfs has several mount options specifically relevant to SSDs. Aside from the obvious trim support, they are ssd and ssd_spread. The documentation on this is vague and my attempts to learn more about it found a lot of information that was outdated or unsubstantiated folklore. Some reports suggest that older SSDs will benefit from ssd_spread, but that it may have no effect or even a harmful effect on newer ones, and can at times cause fragmentation or write amplification. I could find nothing to back this up, though. And it seems particularly difficult to figure out what kind of wear leveling SSD firmware does. MicroSD firmware is likely to be on the less-advanced side, but still, I have no idea what it might do. In any case, with btrfs not updating blocks in-place, it should be better than ext4 in the most naive case (no wear leveling at all) but may have somewhat more write traffic for the pathological worst case (frequent updates of small portions of large files). One anecdotal report I read and can t find anymore, somehow was from a person that had set up a sort of torture test for SD cards, with reports that ext4 lasted a few weeks or months before the MicroSDs failed, while btrfs lasted years. If you are looking for a MicroSD card, by the way, The Great MicroSD Card Survey is a nice place to start. For longevity: I mount all my filesystems with noatime already, so I continue to recommend that. You can also consider limiting the log size in /etc/systemd/journald.conf, running daily fstrim (which may be more successful than live trims in all filesystems). Conclusion I ve been pretty pleased with btrfs. The concerns I have today relate to block groups and maintenance (periodic balance and maybe a periodic defrag). I m not sure I d be ready to say put btrfs on the computer you send to someone that isn t Linux-savvy because the chances of running into issues are higher than with ext4. Still, for people that have some tech savvy, btrfs can improve reliability and performance in other ways.

6 September 2025

Reproducible Builds: Reproducible Builds in August 2025

Welcome to the August 2025 report from the Reproducible Builds project! Welcome to the latest report from the Reproducible Builds project for August 2025. These monthly reports outline what we ve been up to over the past month, and highlight items of news from elsewhere in the increasingly-important area of software supply-chain security. If you are interested in contributing to the Reproducible Builds project, please see the Contribute page on our website. In this report:

  1. Reproducible Builds Summit 2025
  2. Reproducible Builds and live-bootstrap at WHY2025
  3. DALEQ Explainable Equivalence for Java Bytecode
  4. Reproducibility regression identifies issue with AppArmor security policies
  5. Rust toolchain fixes
  6. Distribution work
  7. diffoscope
  8. Website updates
  9. Reproducibility testing framework
  10. Upstream patches

Reproducible Builds Summit 2025 Please join us at the upcoming Reproducible Builds Summit, set to take place from October 28th 30th 2025 in Vienna, Austria!** We are thrilled to host the eighth edition of this exciting event, following the success of previous summits in various iconic locations around the world, including Venice, Marrakesh, Paris, Berlin, Hamburg and Athens. Our summits are a unique gathering that brings together attendees from diverse projects, united by a shared vision of advancing the Reproducible Builds effort. During this enriching event, participants will have the opportunity to engage in discussions, establish connections and exchange ideas to drive progress in this vital field. Our aim is to create an inclusive space that fosters collaboration, innovation and problem-solving. If you re interesting in joining us this year, please make sure to read the event page which has more details about the event and location. Registration is open until 20th September 2025, and we are very much looking forward to seeing many readers of these reports there!

Reproducible Builds and live-bootstrap at WHY2025 WHY2025 (What Hackers Yearn) is a nonprofit outdoors hacker camp that takes place in Geestmerambacht in the Netherlands (approximately 40km north of Amsterdam). The event is organised for and by volunteers from the worldwide hacker community, and knowledge sharing, technological advancement, experimentation, connecting with your hacker peers, forging friendships and hacking are at the core of this event . At this year s event, Frans Faase gave a talk on live-bootstrap, an attempt to provide a reproducible, automatic, complete end-to-end bootstrap from a minimal number of binary seeds to a supported fully functioning operating system . Frans talk is available to watch on video and his slides are available as well.

DALEQ Explainable Equivalence for Java Bytecode Jens Dietrich of the Victoria University of Wellington, New Zealand and Behnaz Hassanshahi of Oracle Labs, Australia published an article this month entitled DALEQ Explainable Equivalence for Java Bytecode which explores the options and difficulties when Java binaries are not identical despite being from the same sources, and what avenues are available for proving equivalence despite the lack of bitwise correlation:
[Java] binaries are often not bitwise identical; however, in most cases, the differences can be attributed to variations in the build environment, and the binaries can still be considered equivalent. Establishing such equivalence, however, is a labor-intensive and error-prone process.
Jens and Behnaz therefore propose a tool called DALEQ, which:
disassembles Java byte code into a relational database, and can normalise this database by applying Datalog rules. Those databases can then be used to infer equivalence between two classes. Notably, equivalence statements are accompanied with Datalog proofs recording the normalisation process. We demonstrate the impact of DALEQ in an industrial context through a large-scale evaluation involving 2,714 pairs of jars, comprising 265,690 class pairs. In this evaluation, DALEQ is compared to two existing bytecode transformation tools. Our findings reveal a significant reduction in the manual effort required to assess non-bitwise equivalent artifacts, which would otherwise demand intensive human inspection. Furthermore, the results show that DALEQ outperforms existing tools by identifying more artifacts rebuilt from the same code as equivalent, even when no behavioral differences are present.
Jens also posted this news to our mailing list.

Reproducibility regression identifies issue with AppArmor security policies Tails developer intrigeri has tracked and followed a reproducibility regression in the generation of AppArmor policy caches, and has identified an issue with the 4.1.0 version of AppArmor. Although initially tracked on the Tails issue tracker, intrigeri filed an issue on the upstream bug tracker. AppArmor developer John Johansen replied, confirming that they can reproduce the issue and went to work on a draft patch. Through this, John revealed that it was caused by an actual underlying security bug in AppArmor that is to say, it resulted in permissions not (always) matching what the policy intends and, crucially, not merely a cache reproducibility issue. Work on the fix is ongoing at time of writing.

Rust toolchain fixes Rust Clippy is a linting tool for the Rust programming language. It provides a collection of lints (rules) designed to identify common mistakes, stylistic issues, potential performance problems and unidiomatic code patterns in Rust projects. This month, however, Sosth ne Gu don filed a new issue in the GitHub requesting a new check that would lint against non deterministic operations in proc-macros, such as iterating over a HashMap .

Distribution work In Debian this month: Lastly, Bernhard M. Wiedemann posted another openSUSE monthly update for their work there.

diffoscope diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues. This month, Chris Lamb made the following changes, including preparing and uploading versions, 303, 304 and 305 to Debian:
  • Improvements:
    • Use sed(1) backreferences when generating debian/tests/control to avoid duplicating ourselves. [ ]
    • Move from a mono-utils dependency to versioned mono-devel mono-utils dependency, taking care to maintain the [!riscv64] architecture restriction. [ ]
    • Use sed over awk to avoid mangling dependency lines containing = (equals) symbols such as version restrictions. [ ]
  • Bug fixes:
    • Fix a test after the upload of systemd-ukify version 258~rc3. [ ]
    • Ensure that Java class files are named .class on the filesystem before passing them to javap(1). [ ]
    • Do not run jsondiff on files over 100KiB as the algorithm runs in O(n^2) time. [ ]
    • Don t check for PyPDF version 3 specifically; check for >= 3. [ ]
  • Misc:
    • Update copyright years. [ ][ ]
In addition, Martin Joerg fixed an issue with the HTML presenter to avoid crash when page limit is None [ ] and Zbigniew J drzejewski-Szmek fixed compatibility with RPM 6 [ ]. Lastly, John Sirois fixed a missing requests dependency in the trydiffoscope tool. [ ]

Website updates Once again, there were a number of improvements made to our website this month including:

Reproducibility testing framework The Reproducible Builds project operates a comprehensive testing framework running primarily at tests.reproducible-builds.org in order to check packages and other artifacts for reproducibility. In August, however, a number of changes were made by Holger Levsen, including:
  • reproduce.debian.net-related:
    • Run 4 workers on the o4 node again in order to speed up testing. [ ][ ][ ][ ]
    • Also test trixie-proposed-updates and trixie-updates etc. [ ][ ]
    • Gather seperate statistics for each tested release. [ ]
    • Support sources from all Debian suites. [ ]
    • Run new code from the prototype database rework branch for the amd64-pull184 pseudo-architecture. [ ][ ]
    • Add a number of helpful links. [ ][ ][ ][ ][ ][ ][ ][ ][ ]
    • Temporarily call debrebuild without the --cache argument to experiment with a new version of devscripts. [ ][ ][ ]
    • Update public TODO. [ ]
  • Installation tests:
    • Add comments to explain structure. [ ]
    • Mark more old jobs as old or dead . [ ][ ][ ]
    • Turn the maintenance job into a no-op. [ ]
  • Jenkins node maintenance:
    • Increase penalties if the osuosl5 or ionos7 nodes are down. [ ]
    • Stop trying to fix network automatically. [ ]
    • Correctly mark ppc64el architecture nodes when down. [ ]
    • Upgrade the remaining arm64 nodes to Debian trixie in anticipation of the release. [ ][ ]
    • Allow higher SSD temperatures on the riscv64 architecture. [ ]
  • Debian-related:
    • Drop the armhf architecture; many thanks to Vagrant for physically hosting the nodes for ten years. [ ][ ]
    • Add Debian forky, and archive bullseye. [ ][ ][ ][ ][ ][ ][ ]
    • Document the filesystem space savings from dropping the armhf architecture. [ ]
    • Exclude i386 and armhfr from JSON results. [ ]
    • Update TODOs for when Debian trixie and forky have been released. [ ][ ]
  • tests.reproducible-builds.org-related:
  • Misc:
    • Detect errors with openQA erroring out. [ ]
    • Drop the long-disabled openwrt_rebuilder jobs. [ ]
    • Use qa-jenkins-dev@alioth-lists.debian.net as the contact for jenkins.debian.net. [ ]
    • Redirect reproducible-builds.org/vienna25 to reproducible-builds.org/vienna2025. [ ]
    • Disable all OpenWrt reproducible CI jobs, in coordination with the OpenWrt community. [ ][ ]
    • Make reproduce.debian.net accessable via IPv6. [ ]
    • Ignore that the megacli RAID controller requires packages from Debian bookworm. [ ]
In addition,
  • James Addison migrated away from deprecated toplevel deb822 Python module in favour of debian.deb822 in the bin/reproducible_scheduler.py script [ ] and removed a note on reproduce.debian.net note after the release of Debian trixie [ ].
  • Jochen Sprickerhof made a huge number of improvements to the reproduce.debian.net statistics calculation [ ][ ][ ][ ][ ][ ] as well as to the reproduce.debian.net service more generally [ ][ ][ ][ ][ ][ ][ ][ ].
  • Mattia Rizzolo performed a lot of work migrating scripts to SQLAlchemy version 2.0 [ ][ ][ ][ ][ ][ ] in addition to making some changes to the way openSUSE reproducibility tests are handled internally. [ ]
  • Lastly, Roland Clobus updated the Debian Live packages after the release of Debian trixie. [ ][ ]

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:

Finally, 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:

5 September 2025

Antonio Terceiro: Past halfway there: history of autopkgtest support in Debian

The Release of Debian 13 ("Trixie") last month marked another milestone on the effort to provide automated test support for Debian packages in their installed form. We have achieved the mark of 57% of the source packages in the archive declaring support for autopkgtest.
Release Packages with tests Total number of packages % of packages with tests
wheezy 5 17175 0%
jessie 1112 20596 5%
stretch 5110 24845 20%
buster 9966 28501 34%
bullseye 13949 30943 45%
bookworm 17868 34341 52%
trixie 21527 37670 57%
The code that generated this table is provided at the bottom. The growth rate has been consistently decreasing at each release after stretch. That probably means that the low hanging fruit -- adding support en masse for large numbers of similar packages, such as team-maintained packages for a given programming language -- has been picked, and from now on the work gets slightly harder. Perhaps there is a significant long tail of packages that will never get autopkgtest support. Looking for common prefixes among the packages missing a Testsuite: field gives me us the largest groups of packages missing autopkgtest support: 
$ grep-dctrl -v -F Testsuite --regex -s Package -n . trixie   cut -d - -f 1   uniq -c   sort -n  tail -20
     50 apertium
     50 kodi
     51 lomiri
     53 maven
     55 libjs
     57 globus
     66 cl
     67 pd
     72 lua
     79 php
     88 puppet
     91 r
    111 gnome
    124 ruby
    140 ocaml
    152 rust
    178 golang
    341 fonts
    557 python
   1072 haskell
There seems to be a fair amount of Haskell and Python. If someone could figure out a way of testing installed fonts in a meaningful way, this would a be a good niche where we can cover 300+ packages. There is a another analysis that can be made, which I didn't: which percentage of new packages introduced in a given release have declared autopkgtest support, compared with the total of new packages in that release? My data only counts the totals, so we start with the technical debt of the almost all of the 17,000 packages with no tests in wheezy, which was the stable at the time I started Debian CI. How many of those got tests since then? Note that not supporting autopkgtest does not mean that a package is not tested at all: it can run build-time tests, which are also useful. Not supporting autopkgtest, though, means that their binaries in the archive can't be automatically tested in their installed, but then there is a entire horde of volunteers running testing and unstable on a daily basis who test Debian and report bugs. This is the script that produced the table in the beginning of this post: 
#!/bin/sh
set -eu
extract()  
  local release
  local url
  release="$1"
  url="$2"
  if [ ! -f "$ release " ]; then
    rm -f "$ release .gz"
    curl --silent -o $ release .gz "$ url "
    gunzip "$ release .gz"
  fi
  local with_tests
  local total
  with_tests="$(grep-dctrl -c -F Testsuite --regex . $release)"
  total="$(grep-dctrl -c -F Package --regex . $release)"
  echo "  $ release    $ with_tests    $ total    $((100*with_tests/total))%  "
 
echo "  **Release**   **Packages with tests**   **Total number of packages**   **% of packages with tests**  "
echo " ------------- ------------------------- ------------------------------ ------------------------------ "
for release in wheezy jessie stretch buster; do
  extract "$ release " "http://archive.debian.org/debian/dists/$ release /main/source/Sources.gz"
done
for release in bullseye bookworm trixie; do
  extract "$ release " "http://ftp.br.debian.org/debian/dists/$ release /main/source/Sources.gz"
done

4 September 2025

Noah Meyerhans: False Positives

There are times when an email based workflow gets really difficult. One of those times is when discussing projects related to spam and malware detection. 
 noahm@debian.org
host stravinsky.debian.org [2001:41b8:202:deb::311:108]
SMTP error from remote mail server after end of data:
550-malware detected: Sanesecurity.Phishing.Fake.30934.1.UNOFFICIAL:
550 message rejected
submit@bugs.debian.org
host stravinsky.debian.org [2001:41b8:202:deb::311:108]
SMTP error from remote mail server after end of data:
550-malware detected: Sanesecurity.Phishing.Fake.30934.1.UNOFFICIAL:
550 message rejected
This was, in fact, a false positive. And now, because reportbug doesn t record outgoing messages locally, I need to retype the whole thing. (NB. this is not a complaint about the policies deployed on the Debian mail servers; they d be negligent if they didn t implement such policies on today s internet.)

3 September 2025

Joachim Breitner: F91 in Lean

Back in March, with version 4.17.0, Lean introduced partial_fixpoint, a new way to define recursive functions. I had drafted a blog post for the official Lean FRO blog back then, but forgot about it, and with the Lean FRO blog discontinued, I ll just publish it here, better late than never. With the partial_fixpoint mechanism we can model possibly partial functions (so those returning an Option) without an explicit termination proof, and still prove facts about them. See the corresponding section in the reference manual for more details. On the Lean Zulip, I was asked if we can use this feature to define the McCarthy 91 function and prove it to be total. This function is a well-known tricky case for termination proofs. First let us have a brief look at why this function is tricky to define in a system like Lean. A naive definition like 
def f91 (n : Nat) : Nat :=
  if n > 100
  then n - 10
  else f91 (f91 (n + 11))
does not work; Lean is not able to prove termination of this functions by itself. Even using well-founded recursion with an explicit measure (e.g. termination_by 101 - n) is doomed, because we would have to prove facts about the function s behaviour (namely that f91n = f91101 = 91 for 90 n 100) and at the same time use that fact in the termination proof that we have to provide while defining the function. (The Wikipedia page spells out the proof.) We can make well-founded recursion work if we change the signature and use a subtype on the result to prove the necessary properties while we are defining the function. Lean by Example shows how to do it, but for larger examples this approach can be hard or tedious. With partial_fixpoint, we can define the function as a partial function without worrying about termination. This requires a change to the function s signature, returning an Option Nat: 
def f91 (n : Nat) : Option Nat :=
  if n > 100
    then pure (n - 10)
    else f91 (n + 11) >>= f91
partial_fixpoint
From the point of view of the logic, Option.none is then used for those inputs for which the function does not terminate. This function definition is accepted and the function runs fine as compiled code: 
#eval f91 42
prints some 91. The crucial question is now: Can we prove anything about f91 In particular, can we prove that this function is actually total? Since we now have the f91 function defined, we can start proving auxillary theorems, using whatever induction schemes we need. In particular we can prove that f91 is total and always returns 91 for n 100: 
theorem f91_spec_high (n : Nat) (h : 100 < n) : f91 n = some (n - 10) := by
  unfold f91; simp [*]
theorem f91_spec_low (n : Nat) (h  : n   100) : f91 n = some 91 := by
  unfold f91
  rw [if_neg (by omega)]
  by_cases n < 90
    rw [f91_spec_low (n + 11) (by omega)]
    simp only [Option.bind_eq_bind, Option.some_bind]
    rw [f91_spec_low 91 (by omega)]
    rw [f91_spec_high (n + 11) (by omega)]
    simp only [Nat.reduceSubDiff, Option.some_bind]
    by_cases h : n = 100
      simp [f91, *]
      exact f91_spec_low (n + 1) (by omega)
theorem f91_spec (n : Nat) : f91 n = some (if n   100 then 91 else n - 10) := by
  by_cases h100 : n   100
    simp [f91_spec_low, *]
    simp [f91_spec_high, Nat.lt_of_not_le  _ , *]
-- Generic totality theorem
theorem f91_total (n : Nat) : (f91 n).isSome := by simp [f91_spec]
(Note that theorem f91_spec_low is itself recursive in a somewhat non-trivial way, but Lean can figure that out all by itself. Use termination_by? if you are curious.) This is already a solid start! But what if we want a function of type f91! (n : Nat) : Nat, without the Option? Then can derive that from the partial variant, as we have just proved that to be actually total: 
def f91! (n : Nat) : Nat  := (f91 n).get (f91_total n)
theorem f91!_spec (n : Nat) : f91! n = if n   100 then 91 else n - 10 := by
  simp [f91!, f91_spec]
Using partial_fixpoint one can decouple the definition of a function from a termination proof, or even model functions that are not terminating on all inputs. This can be very useful in particular when using Lean for program verification, such as with the aeneas package, where such partial definitions are used to model Rust programs.

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