Search Results: "mkd"

11 July 2026

Reproducible Builds: Reproducible Builds in June 2026

Welcome to the June 2026 report from the Reproducible Builds project! In these reports, we outline the most important things that we have been up to over the past month. As a quick recap about what problem our project intends to solve, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is distributed to end users as pre-compiled binaries. The motivation behind the reproducible builds effort is to ensure no flaws have been introduced during this compilation process by promising identical results are always generated from a given source, thus allowing multiple third-parties to come to a consensus on whether a build was compromised or not. If you are interested in contributing to the project, please visit our Contribute page on our website. In this month s report, we cover:

  1. Only installing reproducible packages with repro-threshold
  2. Distribution work
  3. diffoscope development
  4. From our mailing list
  5. Documentation updates
  6. Patches
  7. Four new scholarly papers


Only installing reproducible packages with repro-threshold A very interesting demonstration is now available showing how you might configure your Debian system to only install packages that have been reproduced by m/n rebuilders. This is implemented via a reproduced+https:// APT transport ( a mechanism for communicating between the APT client and its repository source commonly HTTP):
Every package download is intercepted by repro-threshold, which queries two independent rebuilders for a signed attestation before allowing installation to proceed. [It] is important to note that [an] install will only succeed if all package dependencies are also reproducible.
The demo gives examples of how to quickly experiment with this using a Docker container.

Distribution work In Debian this month: The IzzyOnDroid Android APK repository reached its next milestone this month, now covering 2 out of every 3 apps (66.7%) with reproducible builds. Their documentation for debugging and fixing failed builds has steadily grown as well. More clients have picked up showing reproducibility results (e.g. Droid-ify), and Neo Store now can be configured to stick to only reproducible applications. Further, an independent builder has been added to the build farm, increasing the trust level even more as APK builds can have multiple confirmations now. At the same time, IzzyOnDroid s rbtlog got several new features. The most outstanding is caching for frequently used resources such as reproducible-apk-tools, command-line tools and NodeJS in order to counter ongoing issues with GitHub availability, while at the same time saving bandwidth and build time. This change also enables some other some smaller enhancements such as being able to configure build timeouts per recipe for those builds running longer than the average, release pattern filtering for update checks or having a field for maintainer notes to shortly summing up e.g. why a reproducible build failed.
Lastly, Bernhard M. Wiedemann posted another openSUSE monthly update for their reproducibility work there.

diffoscope development 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 319, 320, 321, 322 and 323 to Debian:
  • Debian adds an extra Flags: line in the output of ocamlobjinfo, so adjust the test for cross-distribution compatibility. [ ]
  • Bump debhelper compatibility level to 14. [ ]
  • Fix compatibility with Ocaml 5.4.1. [ ]
  • Use --long-form-style arguments when calling apktool in order to support apktool version 3. [ ]
  • Support Androguard version 4 and previous versions at the same time. [ ]
  • Update copyright years. [ ]
In addition, Jochen Sprickerhof added better header detection for the Sphinx documentation system [ ], Michael Daniels fixed the tests when run with zipdetails version 4.006 [ ] and Zbigniew J drzejewski-Szmek added a version of the deprecated os.path.commonprefix method [ ]. In addition, Vagrant Cascadian updated diffoscope in GNU Guix to version 321 and 323.
Chris Lamb also made the following changes to strip-nondeterminism, our tool to remove specific non-deterministic results from a completed build:
  • Skip symlinks when manually called via /usr/bin/strip-nondeterminism. (#1139000)
  • Update debian/watch format. [ ]
  • Drop Rules-Requires-Root: no and Priority: optional fields. [ ]
  • Bump Standards-Version to version 4.7.4. [ ]

From our mailing list On our mailing list this month:
  • kpcyrd posted to our mailing list regarding the waves of malware uploads to aur.archlinux.org . Curiously, every incident I looked at used npmjs.com for malware delivery , specifically where the npm package includes an (automatically executed) preinstall script that is an ELF binary.
  • kpcyrd also announced the release of debian-repro-status version 0.4.0, a tool written to give you an approximate idea of how viable it would be to enforce a reproducible packages only update policy for the computer system you ve built :
    The change updates dependencies to the latest versions, and adds support for multiple -H options, to query results from multiple rebuilderd instances. The results are also now fetched concurrently.
  • kpcyrd also reported that, whilst taking a screenshot for the above release, they noticed that the debian:sid container now is 100% reproducible.
  • Finally, kpcyrd also created a pull request against the add-determinism package to update the itertools and zip Python dependencies.

Documentation updates Yet again, there were a number of improvements made to our website this month including:
  • Chris Lamb added a reminder re. using the UTC variants of the Javascript Date methods. [ ]
  • Mattia Rizzolo moved OTF to the old sponsors list. Thank you for your support!. [ ]
  • kpcyrd updated the Rust documentation to recommend using the --release argument for consistency. [ ]

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 applicable or possible. This month, we wrote a large number of such patches, including:

Four new scholarly papers Kenichiro Muto and Kuniyasu Suzaki of the Institute of Information Security in Yokohama, Japan published an interesting paper this month titled Attestable Build Chain: Enabling Trust in Reproducible Builds (PDF). Their abstract is as follows: Ensuring trust in software supply chains requires verifying not only artifacts but also the processes that produce them. Although Reproducible Builds (R-B) require rebuilding to validate artifacts, they cannot verify whether the build was executed with the intended toolchain and inputs and may reproduce unintended or compromised builds without detection. We present Attestable Build Chain, a framework for externally verifying build-time execution without rebuilding. Rather than preventing compromise, it provides verifiable, tamper-evident evidence of actual build-time execution, enabling verification of build process integrity from observed file accesses during the build. [ ]
Julien Malka, Stefano Zacchiroli and Th o Zimmermann published a 50-page report detailing A Decade of Software Reproducibility in the Nix Package Ecosystem:
We find that functional package management enables extremely high rebuildability over time (near-universal ability to reconstitute historical build environments and rebuild software packages), while bitwise reproducibility has steadily improved and reaches a high point in recent years (up to 93% in 2024). Early years show substantially lower bitwise reproducibility, indicating that functional package management alone does not guarantee bitwise-identical outputs, and that the observed high level of bitwise reproducibility is not solely due to the package management approach. Common causes of unreproducibility, both in the rebuildability and bitwise reproducibility dimensions, include management of dates in build and test processes; we quantify their prevalence and other common causes using manual analysis of logs of rebuild failures and automated analysis of diffoscope.
A PDF of their report is available online
Tim Bastin of L3montree GmbH and Jacek Galowicz of Applicative Systems GmbH from DevGuard published a paper detailing How We Built a Sovereign, Reproducible Container Supply Chain for DevGuard:
This paper presents how the DevGuard project rebuilt its OCI container pipeline around reproducible Nix builds and independent dual-platform digest verification. DevGuard images are built hermetically from pinned source revisions, signed with Sigstore/Cosign, and verified through digest comparison across GitHub Actions and sovereign GitLab infrastructure hosted on container.gov.de. We describe the practical integration of reproducible OCI image builds into existing CI/CD workflows and argue that independently reproducible container digests provide a stronger integrity guarantee against build tampering than provenance alone. The paper further discusses remaining trust assumptions and the relevance of sovereign build infrastructure for government and regulated environments.

Finally, Yiseul Choi, Junga Kim, Jun-Ho Hong and Seongmin Kim of the Department of Convergence Security Engineering at the Sungshin Women s University in Seoul, Korea titled Attestation-based verification of SBOM integrity via consumer-side reproducibility:
Software bills of materials (SBOMs) support supply chain transparency, but they do not prove that a delivered SBOM reproducibly corresponds to its software artifact. Existing signing and provenance mechanisms protect integrity and traceability, yet lack consumer-side reproducible verification. We propose an SBOM integrity verification framework combining procedure disclosure, consumer-side reproduction, authority-generated reference evidence, and digest comparison. A trusted authority records a reference digest, and consumers compare it with locally reproduced and delivered SBOM digests. Experiments on 100 real-world container images show detection of artifact tampering, SBOM substitution, distribution modification, and adaptive tampering beyond signature-based approaches


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:

10 June 2026

Colin Watson: Free software activity in May 2026

My Debian contributions this month were all sponsored by Freexian. You can also support my work directly via Liberapay or GitHub Sponsors. OpenSSH I backported various security fixes from 10.3 to trixie, bookworm, bullseye, buster, and stretch. For trixie, I also backported several IPQoS fixes to line up with upstream s traffic management settings and drop a rather hacky Debian-specific patch; this needed a quick follow-up fix. I upgraded trixie-backports to 10.3. I fixed openssh uses pidof but does not depend on procps. PuTTY I upgraded from 0.83 to 0.84. Python packaging New upstream versions: Other build/test failures: Other bugs: I updated python-treq upstream to stop vendoring multipart, now that the packaging issues with that have been sorted out. Code reviews Other bits and pieces I contributed a debian-policy patch to fix several links related to build profiles.

4 June 2026

Jonathan Dowland: mount namespace for backup jobs (by hand)

It's been ten years since I configured mount on demand backups to reduce the risk of my backups being zapped by mistake. Way back then I wanted to go one step further and use dedicated mount namespaces for backup jobs, but systemd didn't provide the necessary support (and still doesn't, despite the promisingly-named JoinsNameSpaceOf= configuration option.) I recently updated my setup to achieve this by hand. All backup jobs now have an extra pre-start instruction ExecStartPre=mkbackupns which runs a shell script to either set up a persistent mount namespace, or exit quietly if it already exists.
#!/bin/bash
set -euo pipefail
nsdir=/var/namespaces
nsfile=$nsdir/backup
nsfilex="$(echo $nsfile   sed 's#/#\\/#'g)"
private_propagation()  
    findmnt -o+PROPAGATION "$nsdir"   grep -q private
 
nsfs_is_mounted()  
    test "nsfs" = "$(awk "/$nsfilex/   print \$3  " /proc/mounts)"
 
if ! nsfs_is_mounted; then
    if ! private_propagation; then
        mkdir -p "$nsdir"
        mount --bind --make-private "$nsdir" "$nsdir"
    fi
    touch "$nsfile"
    unshare --mount="$nsfile" true
    nsenter --mount=/var/namespaces/backup mount /dev/phobos_backup/backup /backup
fi
I should note that I don't have the backup filesystem described in /etc/fstab to reduce the risk of it being mounted errantly in the main namespace. The other change is to prefix an invocation of nsenter for every backup job command. E.g.:
ExecStart=/usr/bin/nsenter \
        --mount=/var/namespaces/backup \
        borgmatic -v 1 prune create
next steps My backup scheme has lasted a decade with few tweaks (I moved it to Borg in 2020) which I am very grateful for. I want reliable, boring and robust. Persistent mount namespaces are a lot less convoluted if you have a persistent process to associate them with. I didn't, but a subsequent improvement I am making is introducing one, so I will likely simplify the above accordingly.

9 March 2026

Dirk Eddelbuettel: nanotime 0.3.13 on CRAN: Maintenance

Another minor update 0.3.13 for our nanotime package is now on CRAN, and has been uploaded to Debian and compiled for r2u. nanotime relies on the RcppCCTZ package (as well as the RcppDate package for additional C++ operations) and offers efficient high(er) resolution time parsing and formatting up to nanosecond resolution, using the bit64 package for the actual integer64 arithmetic. Initially implemented using the S3 system, it has benefitted greatly from a rigorous refactoring by Leonardo who not only rejigged nanotime internals in S4 but also added new S4 types for periods, intervals and durations. This release, the first in eleven months, rounds out a few internal corners and helps Rcpp with the transition away from Rf_error to only using Rcpp::stop which deals more gracefully with error conditions and unwinding. We also updated how the vignette is made, its references, updated the continuous integration as one does, altered how the documentation site is built, gladly took a PR from Michael polishing another small aspect, and tweaked how the compilation standard is set. The NEWS snippet below has the fuller details.

Changes in version 0.3.13 (2026-03-08)
  • The methods package is now a Depends as WRE recommends (Michael Chirico in #141 based on a suggestion by Dirk in #140)
  • The mkdocs-material documentation site is now generated via altdoc
  • Continuous Integration scripts have been updated
  • Replace Rf_error with Rcpp::stop, turn remaining one into (Rf_error) (Dirk in #143)
  • Vignette now uses the Rcpp::asis builder for pre-made pdfs (Dirk in #146 fixing #144)
  • The C++ compilation standard is explicitly set to C++17 if an R version older than 4.3.0 is used (Dirk in #148 fixing #147)
  • The vignette references have been updated

Thanks to my CRANberries, there is a diffstat report for this release. More details and examples are at the nanotime page; code, issue tickets etc at the GitHub repository and all documentation is provided at the nanotime documentation site.

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.

8 February 2026

Colin Watson: Free software activity in January 2026

About 80% of my Debian contributions this month were sponsored by Freexian, as well as one direct donation via GitHub Sponsors (thanks!). If you appreciate this sort of work and are at a company that uses Debian, have a look to see whether you can pay for any of Freexian s services; as well as the direct benefits, that revenue stream helps to keep Debian development sustainable for me and several other lovely people. You can also support my work directly via Liberapay or GitHub Sponsors. Python packaging New upstream versions: Fixes for Python 3.14: Fixes for pytest 9: Porting away from the deprecated pkg_resources: Other build/test failures: I investigated several more build failures and suggested removing the packages in question: Other bugs: Other bits and pieces Alejandro Colomar reported that man(1) ignored the MANWIDTH environment variable in some circumstances. I investigated this and fixed it upstream. I contributed an ubuntu-dev-tools patch to stop recommending sudo. I added forky support to the images used in Salsa CI pipelines. I began working on getting a release candidate of groff 1.24.0 into experimental, though haven t finished that yet. I worked on some lower-priority security updates for OpenSSH. Code reviews

31 January 2026

Michael Prokop: apt, SHA-1 keys + 2026-02-01

You might have seen Policy will reject signature within a year warnings in apt(-get) update runs like this:
root@424812bd4556:/# apt update
Get:1 http://foo.example.org/debian demo InRelease [4229 B]
Hit:2 http://deb.debian.org/debian trixie InRelease
Hit:3 http://deb.debian.org/debian trixie-updates InRelease
Hit:4 http://deb.debian.org/debian-security trixie-security InRelease
Get:5 http://foo.example.org/debian demo/main amd64 Packages [1097 B]
Fetched 5326 B in 0s (43.2 kB/s)
All packages are up to date.
Warning: http://foo.example.org/debian/dists/demo/InRelease: Policy will reject signature within a year, see --audit for details
root@424812bd4556:/# apt --audit update
Hit:1 http://foo.example.org/debian demo InRelease
Hit:2 http://deb.debian.org/debian trixie InRelease
Hit:3 http://deb.debian.org/debian trixie-updates InRelease
Hit:4 http://deb.debian.org/debian-security trixie-security InRelease
All packages are up to date.    
Warning:  http://foo.example.org/debian/dists/demo/InRelease: Policy will reject signature within a year, see --audit for details
Audit:  http://foo.example.org/debian/dists/demo/InRelease: Sub-process /usr/bin/sqv returned an error code (1), error message is:
   Signing key on 54321ABCD6789ABCD0123ABCD124567ABCD89123 is not bound:
              No binding signature at time 2024-06-19T10:33:47Z
     because: Policy rejected non-revocation signature (PositiveCertification) requiring second pre-image resistance
     because: SHA1 is not considered secure since 2026-02-01T00:00:00Z
Audit: The sources.list(5) entry for 'http://foo.example.org/debian' should be upgraded to deb822 .sources
Audit: Missing Signed-By in the sources.list(5) entry for 'http://foo.example.org/debian'
Audit: Consider migrating all sources.list(5) entries to the deb822 .sources format
Audit: The deb822 .sources format supports both embedded as well as external OpenPGP keys
Audit: See apt-secure(8) for best practices in configuring repository signing.
Audit: Some sources can be modernized. Run 'apt modernize-sources' to do so.
If you ignored this for the last year, I would like to tell you that 2026-02-01 is not that far away (hello from the past if you re reading this because you re already affected). Let s simulate the future:
root@424812bd4556:/# apt --update -y install faketime
[...]
root@424812bd4556:/# export LD_PRELOAD=/usr/lib/x86_64-linux-gnu/faketime/libfaketime.so.1 FAKETIME="2026-08-29 23:42:11" 
root@424812bd4556:/# date
Sat Aug 29 23:42:11 UTC 2026
root@424812bd4556:/# apt update
Get:1 http://foo.example.org/debian demo InRelease [4229 B]
Hit:2 http://deb.debian.org/debian trixie InRelease                                 
Err:1 http://foo.example.org/debian demo InRelease
  Sub-process /usr/bin/sqv returned an error code (1), error message is: Signing key on 54321ABCD6789ABCD0123ABCD124567ABCD89123 is not bound:            No binding signature at time 2024-06-19T10:33:47Z   because: Policy rejected non-revocation signature (PositiveCertification) requiring second pre-image resistance   because: SHA1 is not considered secure since 2026-02-01T00:00:00Z
[...]
Warning: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. OpenPGP signature verification failed: http://foo.example.org/debian demo InRelease: Sub-process /usr/bin/sqv returned an error code (1), error message is: Signing key on 54321ABCD6789ABCD0123ABCD124567ABCD89123 is not bound:            No binding signature at time 2024-06-19T10:33:47Z   because: Policy rejected non-revocation signature (PositiveCertification) requiring second pre-image resistance   because: SHA1 is not considered secure since 2026-02-01T00:00:00Z
[...]
root@424812bd4556:/# echo $?
100
Now, the proper solution would have been to fix the signing key underneath (via e.g. sq cert lint &dash&dashfix &dash&dashcert-file $PRIVAT_KEY_FILE > $PRIVAT_KEY_FILE-fixed). If you don t have access to the according private key (e.g. when using an upstream repository that has been ignoring this issue), you re out of luck for a proper fix. But there s a workaround for the apt situation (related see apt commit 0989275c2f7afb7a5f7698a096664a1035118ebf):
root@424812bd4556:/# cat /usr/share/apt/default-sequoia.config
# Default APT Sequoia configuration. To overwrite, consider copying this
# to /etc/crypto-policies/back-ends/apt-sequoia.config and modify the
# desired values.
[asymmetric_algorithms]
dsa2048 = 2024-02-01
dsa3072 = 2024-02-01
dsa4096 = 2024-02-01
brainpoolp256 = 2028-02-01
brainpoolp384 = 2028-02-01
brainpoolp512 = 2028-02-01
rsa2048  = 2030-02-01
[hash_algorithms]
sha1.second_preimage_resistance = 2026-02-01    # Extend the expiry for legacy repositories
sha224 = 2026-02-01
[packets]
signature.v3 = 2026-02-01   # Extend the expiry
Adjust this according to your needs:
root@424812bd4556:/# mkdir -p /etc/crypto-policies/back-ends/
root@424812bd4556:/# cp /usr/share/apt/default-sequoia.config /etc/crypto-policies/back-ends/apt-sequoia.config
root@424812bd4556:/# $EDITOR /etc/crypto-policies/back-ends/apt-sequoia.config
root@424812bd4556:/# cat /etc/crypto-policies/back-ends/apt-sequoia.config
# APT Sequoia override configuration
[asymmetric_algorithms]
dsa2048 = 2024-02-01
dsa3072 = 2024-02-01
dsa4096 = 2024-02-01
brainpoolp256 = 2028-02-01
brainpoolp384 = 2028-02-01
brainpoolp512 = 2028-02-01
rsa2048  = 2030-02-01
[hash_algorithms]
sha1.second_preimage_resistance = 2026-09-01    # Extend the expiry for legacy repositories
sha224 = 2026-09-01
[packets]
signature.v3 = 2026-02-01   # Extend the expiry
Then we re back into the original situation, being a warning instead of an error:
root@424812bd4556:/# apt update
Hit:1 http://deb.debian.org/debian trixie InRelease
Get:2 http://foo.example.org/debian demo InRelease [4229 B]
Hit:3 http://deb.debian.org/debian trixie-updates InRelease
Hit:4 http://deb.debian.org/debian-security trixie-security InRelease
Warning: http://foo.example.org/debian/dists/demo/InRelease: Policy will reject signature within a year, see --audit for details
[..]
Please note that this is a workaround, and not a proper solution.

5 January 2026

Colin Watson: Free software activity in December 2025

About 95% of my Debian contributions this month were sponsored by Freexian. You can also support my work directly via Liberapay or GitHub Sponsors. Python packaging I upgraded these packages to new upstream versions: Python 3.14 is now a supported version in unstable, and we re working to get that into testing. As usual this is a pretty arduous effort because it requires going round and fixing lots of odds and ends across the whole ecosystem. We can deal with a fair number of problems by keeping up with upstream (see above), but there tends to be a long tail of packages whose upstreams are less active and where we need to chase them, or where problems only show up in Debian for one reason or another. I spent a lot of time working on this: Fixes for pytest 9: I filed lintian: Report Python egg-info files/directories to help us track the migration to pybuild-plugin-pyproject. I did some work on dh-python: Normalize names in pydist lookups and pyproject plugin: Support headers (the latter of which allowed converting python-persistent and zope.proxy to pybuild-plugin-pyproject, although it needed a follow-up fix). I fixed or helped to fix several other build/test failures: Other bugs: Other bits and pieces Code reviews

24 December 2025

Daniel Lange: Getting scanning to work with Gimp on Trixie

Trixie ships Gimp 3.0.4 and the 3.x series has gotten incompatible to XSane, the common frontend for scanners on Linux. Hence the maintainer, J rg Frings-F rst, has disabled the Gimp integration temporarily in response to a Debian bug #1088080. There seems to be no tracking bug for getting the functionality back but people have been commenting on Debian bug #993293 as that is ... loosely related :-). There are two options to get the Scanning functionality back in Trixie until this is properly resolved by an updated XSane in Debian (e.g. via trixie-backports): Lee Yingtong Li (RunasSudo) has created a Python script that calls XSane as a cli application and published it at https://yingtongli.me/git/gimp-xsanecli/. This worked okish for me but needed me to find the scan in /tmp/ a number of times. This is a good stop-gap script if you need to scan from Gimp $now and look for a quick solution. Upstream has completed the necessary steps to get XSane working as a Gimp 3.x plugin at https://gitlab.com/sane-project/frontend/xsane. Unfortunately compiling this is a bit involved but I made a version that can be dropped into /usr/local/bin or $HOME/bin and works alongside Gimp and the system-installed XSane. So:
  1. sudo apt install gimp xsane
  2. Download xsane-1.0.0-fit-003 (752kB, AMD64 executable for Trixie) and place it in /usr/local/bin (as root)
  3. sha256sum /usr/local/bin/xsane-1.0.0-fit-003
    # result needs to be af04c1a83c41cd2e48e82d04b6017ee0b29d555390ca706e4603378b401e91b2
  4. sudo chmod +x /usr/local/bin/xsane-1.0.0-fit-003
  5. # Link the executable into the Gimp plugin directory as the user running Gimp:
    mkdir -p $HOME/.config/GIMP/3.0/plug-ins/xsane/
    ln -s /usr/local/bin/xsane-1.0.0-fit-003 $HOME/.config/GIMP/3.0/plug-ins/xsane/
  6. Restart Gimp
  7. Scan from Gimp via File Create Acquire XSane
The source code for the xsane executable above is available under GPL-2 at https://gitlab.com/sane-project/frontend/xsane/-/tree/c5ac0d921606309169067041931e3b0c73436f00. This points to the last upstream commit from 27. September 2025 at the time of writing this blog article.

19 December 2025

Otto Kek l inen: Backtesting trailing stop-loss strategies with Python and market data

Featured image of post Backtesting trailing stop-loss strategies with Python and market dataIn January 2024 I wrote about the insanity of the Magnificent Seven dominating the MSCI World Index, and I wondered how long the number can continue to go up? It has continued to surge upward at an accelerating pace, which makes me worry that a crash is likely closer. As a software professional, I decided to analyze whether using stop-loss orders could reliably automate avoiding deep drawdowns. As everyone with some savings in the stock market (hopefully) knows, the stock market eventually experiences crashes. It is just a matter of when and how deep the crash will be. Staying on the sidelines for years is not a good investment strategy, as inflation will erode the value of your savings. Assuming the current true inflation rate is around 7%, a restaurant dinner that costs 20 euros today will cost 24.50 euros in three years. Savings of 1000 euros today would drop in purchasing power from 50 dinners to only 40 dinners in three years. Hence, if you intend to retain the value of your hard-earned savings, they need to be invested in something that grows in value. Most people try to beat inflation by buying shares in stable companies, directly or via broad market ETFs. These historically grow faster than inflation during normal years, but likely drop in value during recessions.

What is a trailing stop-loss order? What if you could buy stocks to benefit from their value increasing without having to worry about a potential crash? All modern online stock brokers have a feature called stop-loss, where you can enter a price at which your stocks automatically get sold if they drop down to that price. A trailing stop-loss order is similar, but instead of a fixed price, you enter a margin (e.g. 10%). If the stock price rises, the stop-loss price will trail upwards by that margin. For example, if you buy a share at 100 euros and it has risen to 110 euros, you can set a 10% trailing stop-loss order which automatically sells it if the price drops 10% from the peak of 110 euros, at 99 euros. Thus, no matter what happens, you only lost 1 euro. And if the stock price continues to rise to 150 euros, the trailing stop-loss would automatically readjust to 150 euros minus 10%, which is 135 euros (150-15=135). If the price dropped to 135 euros, you would lock in a gain of 35 euros, which is not the peak price of 150 euros, but still better than whatever the price fell down to as a result of a large crash. In the simple case above, it obviously makes sense in theory, but it might not make sense in practice. Prices constantly oscillate, so you don t want a margin that is too small, otherwise you exit too early. Conversely, having a large margin may result in too large a drawdown before exiting. If markets crash rapidly, it might be that nobody buys your stocks at the stop-loss price, and shares have to be sold at an even lower price. Also, what will you do once the position is sold? The reason you invested in the stock market was to avoid holding cash, so would you buy the same stock back when the crash bottoms? But how will you know when the bottom has been reached?

Backtesting stock market strategies with Python, YFinance, Pandas and Lightweight Charts I am not a professional investor, and nobody should take investment advice from me. However, I know what backtesting is and how to leverage open source software. So, I wrote a Python script to test if the trading strategy of using trailing stop-loss orders with specific margin values would have worked for a particular stock. First you need to have data. YFinance is a handy Python library that can be used to download the historic price data for any stock ticker on Yahoo.com. Then you need to manipulate the data. Pandas is the Python data analysis library with advanced data structures for working with relational or labeled data. Finally, to visualize the results, I used Lightweight Charts, which is a fast, interactive library for rendering financial charts, allowing you to plot the stock price, the trailing stop-loss line, and the points where trades would have occurred. I really like how the zoom is implemented in Lightweight Charts, which makes drilling into the data points feel effortless. The full solution is not polished enough to be published for others to use, but you can piece together your own by reusing some of the key snippets. To avoid re-downloading the same data repeatedly, I implemented a small caching wrapper that saves the data locally (as Parquet files):
python
CACHE_DIR.mkdir(parents=True, exist_ok=True)
end_date = datetime.today().strftime("%Y-%m-%d")
cache_file = CACHE_DIR / f" TICKER - START_DATE -- end_date .parquet"

if cache_file.is_file():
 dataframe = pandas.read_parquet(cache_file)
 print(f"Loaded price data from cache:  cache_file ")
else:
 dataframe = yfinance.download(
 TICKER,
 start=START_DATE,
 end=end_date,
 progress=False,
 auto_adjust=False
 )

 dataframe.to_parquet(cache_file)
 print(f"Fetched new price data from Yahoo Finance and cached to:  cache_file ")
The dataframe is a Pandas object with a powerful API. For example, to print a snippet from the beginning and the end of the dataframe to see what the data looks like, you can use:
python
print("First 5 rows of the raw data:")
print(df.head())
print("Last 5 rows of the raw data:")
print(df.tail())
Example output:
First 5 rows of the raw data
Price Adj Close Close High Low Open Volume
Ticker BNP.PA BNP.PA BNP.PA BNP.PA BNP.PA BNP.PA
Date
2014-01-02 29.956285 55.540001 56.910000 55.349998 56.700001 316552
2014-01-03 30.031801 55.680000 55.990002 55.290001 55.580002 210044
2014-01-06 30.080338 55.770000 56.230000 55.529999 55.560001 185142
2014-01-07 30.943321 57.369999 57.619999 55.790001 55.880001 370397
2014-01-08 31.385597 58.189999 59.209999 57.750000 57.790001 489940
Last 5 rows of the raw data
Price Adj Close Close High Low Open Volume
Ticker BNP.PA BNP.PA BNP.PA BNP.PA BNP.PA BNP.PA
Date
2025-12-11 78.669998 78.669998 78.919998 76.900002 76.919998 357918
2025-12-12 78.089996 78.089996 80.269997 78.089996 79.470001 280477
2025-12-15 79.080002 79.080002 79.449997 78.559998 78.559998 233852
2025-12-16 78.860001 78.860001 79.980003 78.809998 79.430000 283057
2025-12-17 80.080002 80.080002 80.150002 79.080002 79.199997 262818
Adding new columns to the dataframe is easy. For example, I used a custom function to calculate the Relative Strength Index (RSI). To add a new column RSI with a value for every row based on the price from that row, only one line of code is needed, without custom loops:
python
df["RSI"] = compute_rsi(df["price"], period=14)
After manipulating the data, the series can be converted into an array structure and printed as JSON into a placeholder in an HTML template:
python
 baseline_series = [
  "time": ts, "value": val 
 for ts, val in df_plot[["timestamp", BASELINE_LABEL]].itertuples(index=False)
 ]

 baseline_json = json.dumps(baseline_series)
 template = jinja2.Template("template.html")
 rendered_html = template.render(
 title=title,
 heading=heading,
 description=description_html,
 ...
 baseline_json=baseline_json,
 ...
 )

 with open("report.html", "w", encoding="utf-8") as f:
 f.write(rendered_html)
 print("Report generated!")
In the HTML template, the marker variable in Jinja syntax gets replaced with the actual JSON:
html
<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>  title  </title>
 ...
</head>
<body>
 <h1>  heading  </h1>
 <div id="chart"></div>
 <script>
 // Ensure the DOM is ready before we initialise the chart
 document.addEventListener('DOMContentLoaded', () =>  
 // Parse the JSON data passed from Python
 const baselineData =   baseline_json   safe  ;
 const strategyData =   strategy_json   safe  ;
 const markersData =   markers_json   safe  ;

 // Create the chart
 const chart = LightweightCharts.createChart(document.getElementById('chart'),  
 width: document.getElementById('chart').clientWidth,
 height: 500,
 layout:  
 background:   color: "#222"  ,
 textColor: "#ccc"
  ,
 grid:  
 vertLines:   color: "#555"  ,
 horzLines:   color: "#555"  
  
  );

 // Add baseline series
 const baselineSeries = chart.addLineSeries( 
 title: '  baseline_label  ',
 lastValueVisible: false,
 priceLineVisible: false,
 priceLineWidth: 1
  );
 baselineSeries.setData(baselineData);

 baselineSeries.priceScale().applyOptions( 
 entireTextOnly: true
  );

 // Add strategy series
 const strategySeries = chart.addLineSeries( 
 title: '  strategy_label  ',
 lastValueVisible: false,
 priceLineVisible: false,
 color: '#FF6D00'
  );
 strategySeries.setData(strategyData);

 // Add buy/sell markers to the strategy series
 strategySeries.setMarkers(markersData);

 // Fit the chart to show the full data range (full zoom)
 chart.timeScale().fitContent();
  )
 </script>
</body>
</html>
There are also Python libraries built specifically for backtesting investment strategies, such as Backtrader and Zipline, but they do not seem to be actively maintained, and probably have too many features and complexity compared to what I needed for doing this simple test. The screenshot below shows an example of backtesting a strategy on the Waste Management Inc stock from January 2015 to December 2025. The baseline Buy and hold scenario is shown as the blue line and it fully tracks the stock price, while the orange line shows how the strategy would have performed, with markers for the sells and buys along the way. Backtest run example

Results I experimented with multiple strategies and tested them with various parameters, but I don t think I found a strategy that was consistently and clearly better than just buy-and-hold. It basically boils down to the fact that I was not able to find any way to calculate when the crash has bottomed based on historical data. You can only know in hindsight that the price has stopped dropping and is on a steady path to recovery, but at that point it is already too late to buy in. In my testing, most strategies underperformed buy-and-hold because they sold when the crash started, but bought back after it recovered at a slightly higher price. In particular when using narrow margins and selling on a 3-6% drawdown the strategy performed very badly, as those small dips tend to recover in a few days. Essentially, the strategy was repeating the pattern of selling 100 stocks at a 6% discount, then being able to buy back only 94 shares the next day, then again selling 94 shares at a 6% discount, and only being able to buy back maybe 90 shares after recovery, and so forth, never catching up to the buy-and-hold. The strategy worked better in large market crashes as they tended to last longer, and there were higher chances of buying back the shares while the price was still low. For example, in the 2020 crash selling at a 20% drawdown was a good strategy, as the stock I tested dropped nearly 50% and remained low for several weeks; thus, the strategy bought back the stocks while the price was still low and had not yet started to climb significantly. But that was just a lucky incident, as the delta between the trailing stop-loss margin of 20% and total crash of 50% was large enough. If the crash had been only 25%, the strategy would have missed the rebound and ended up buying back the stocks at a slightly higher price. Also, note that the simulation assumes that the trade itself is too small to affect the price formation. We should keep in mind that in reality, if many people have stop-loss orders in place, a large price drop would trigger all of them, creating a flood of sell orders, which in turn would affect the price and drive it lower even faster and deeper. Luckily, it seems that stop-loss orders are generally not a good strategy, and we don t need to fear that too many people will be using them.

Conclusion Even though using a trailing stop-loss strategy does not seem to help in getting consistently higher returns based on my backtesting, I would still say it is useful in protecting from the downside of stock investing. It can act as a kind of insurance policy to considerably decrease the chances of losing big while increasing the chances of losing a little bit. If you are risk-averse, which I think I probably am, this tradeoff can make sense. I d rather miss out on an initial 50% loss and an overall 3% gain on recovery than have to sit through weeks or months with a 50% loss before the price recovers to prior levels. Most notably, the trailing stop-loss strategy works best if used only once. If it is repeated multiple times, the small losses in gains will compound into big losses overall. Thus, I think I might actually put this automation in place at least on the stocks in my portfolio that have had the highest gains. If they keep going up, I will ride along, but once the crash happens, I will be out of those particular stocks permanently. Do you have a favorite open source investment tool or are you aware of any strategy that actually works? Comment below!

12 December 2025

Freexian Collaborators: Debian Contributions: Updates about DebConf Video Team Sprint, rebootstrap, SBOM tooling in Debian and more! (by Anupa Ann Joseph)

Debian Contributions: 2025-11 Contributing to Debian is part of Freexian s mission. This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services.

DebConf Video Team Sprint The DebConf Video Team records, streams, and publishes talks from DebConf and many miniDebConfs. A lot of the infrastructure development happens during setup for these events, but we also try to organize a sprint once a year to work on infrastructure, when there isn t a DebConf about to happen. Stefano attended the sprint in Herefordshire this year and wrote up a report.

rebootstrap, by Helmut Grohne A number of jobs were stuck in architecture-specific failures. gcc-15 and dpkg still disagree about whether PIE is enabled occasionally and big endian mipsen needed fixes in systemd. Beyond this regular uploads of libxml2 and gcc-15 required fixes and rebasing of pending patches. Earlier, Loongson used rebootstrap to create the initial package set for loong64 and Miao Wang now submitted their changes. Therefore, there is now initial support for suites other than unstable and use with derivatives.

Building the support for Software Bill Of Materials tooling in Debian, by Santiago Ruano Rinc n Vendors of Debian-based products may/should be paying attention to the evolution of different jurisdictions (such as the CRA or updates on CISA s Minimum Elements for a Software Bill of Materials) that require to make available Software Bill of Materials (SBOM) of their products. It is important then to have tools in Debian to make it easier to produce such SBOMs. In this context, Santiago continued the work on packaging libraries related to SBOMs. This includes the packaging of the SPDX python library (python-spdx-tools), and its dependencies rdflib and mkdocs-include-markdown-plugin. System Package Data Exchange (SPDX), defined by ISO/IEC 5962:2021, is an open standard capable of representing systems with software components as SBOMs and other data and security references. SPDX and CycloneDX (whose python library python3-cyclonedx-lib was packaged by prior efforts this year), encompass the two main SBOM standards available today.

Miscellaneous contributions
  • Carles improved po-debconf-manager: added checking status of bug reports automatically via python-debianbts; changed some command line options naming or output based on user feedback; finished refactoring user interaction to rich; codebase is now flake8-compliant; added type safety with mypy.
  • Carles, using po-debconf-manager, created 19 bug reports for translations where the merge requests were pending; reviewed and created merge requests for 4 packages.
  • Carles planned a second version of the tool that detects packages that Recommends or Suggests packages which are not in Debian. He is taking ideas from dumat.
  • Carles submitted a pull request to python-unidiff2 (adapted from the original pull request to python-unidiff). He also started preparing a qnetload update.
  • Stefano did miscellaneous python package updates: mkdocs-macros-plugin, python-confuse, python-pip, python-mitogen.
  • Stefano reviewed a beets upload for a new maintainer who is taking it over.
  • Stefano handled some debian.net infrastructure requests.
  • Stefano updated debian.social infrastructure for the trixie point release.
  • The update broke jitsi.debian.social, Stefano put some time into debugging it and eventually enlisted upstream assistance, who solved the problem!
  • Stefano worked on some patches for Python that help Debian:
    • GH-139914: The main HP PA-RISC support patch for 3.14.
    • GH-141930: We observed an unhelpful error when failing to write a .pyc file during package installation. We may have fixed the problem, and at least made the error better.
    • GH-141011: Ignore missing ifunc support on HP PA-RISC.
  • Stefano spun up a website for hamburg2026.mini.debconf.org.
  • Rapha l reviewed a merge request updating tracker.debian.org to rely on bootstrap
    version 5.
  • Emilio coordinated various transitions.
  • Helmut sent patches for 26 cross build failures.
  • Helmut officially handed over the cleanup of the /usr-move transition.
  • Helmut monitored the transition moving libcrypt-dev out of build-essential and bumped the remaining bugs to rc-severity in coordination with the release team.
  • Helmut updated the Build-Profiles patch for debian-policy incorporating feedback from Sean Whitton with a lot of help from Nattie Mayer-Hutchings and Freexian colleagues.
  • Helmut discovered that the way mmdebstrap deals with start-stop-daemon may result in broken output and sent a patch.
  • As a result of armel being removed from sid , but not from forky , the multiarch hinter broke. Helmut fixed it.
  • Helmut uploaded debvm accepting a patch from Luca Boccassi to fix it for newer
    systemd.
  • Colin began preparing for the second stage of the OpenSSH GSS-API key exchange package split.
  • Colin caught and fixed a devscripts regression due to it breaking part of Debusine.
  • Colin packaged django-pgtransaction and backported it to trixie , since it looks useful for Debusine.
  • Thorsten uploaded the packages lprng, cpdb-backend-cups, cpdb-libs and ippsample to fix some RC bugs as well as other bugs that accumulated over time. He also uploaded cups-filters to all Debian releases to fix three CVEs.

7 December 2025

Vincent Bernat: Compressing embedded files in Go

Go s embed feature lets you bundle static assets into an executable, but it stores them uncompressed. This wastes space: a web interface with documentation can bloat your binary by dozens of megabytes. A proposition to optionally enable compression was declined because it is difficult to handle all use cases. One solution? Put all the assets into a ZIP archive!

Code The Go standard library includes a module to read and write ZIP archives. It contains a function that turns a ZIP archive into an io/fs.FS structure that can replace embed.FS in most contexts.1
package embed
import (
  "archive/zip"
  "bytes"
  _ "embed"
  "fmt"
  "io/fs"
  "sync"
)
//go:embed data/embed.zip
var embeddedZip []byte
var dataOnce = sync.OnceValue(func() *zip.Reader  
  r, err := zip.NewReader(bytes.NewReader(embeddedZip), int64(len(embeddedZip)))
  if err != nil  
    panic(fmt.Sprintf("cannot read embedded archive: %s", err))
   
  return r
 )
func Data() fs.FS  
  return dataOnce()
 
We can build the embed.zip archive with a rule in a Makefile. We specify the files to embed as dependencies to ensure changes are detected.
common/embed/data/embed.zip: console/data/frontend console/data/docs
common/embed/data/embed.zip: orchestrator/clickhouse/data/protocols.csv 
common/embed/data/embed.zip: orchestrator/clickhouse/data/icmp.csv
common/embed/data/embed.zip: orchestrator/clickhouse/data/asns.csv
common/embed/data/embed.zip:
    mkdir -p common/embed/data && zip --quiet --recurse-paths --filesync $@ $^
The automatic variable $@ is the rule target, while $^ expands to all the dependencies, modified or not.

Space gain Akvorado, a flow collector written in Go, embeds several static assets:
  • CSV files to translate port numbers, protocols or AS numbers, and
  • HTML, CSS, JS, and image files for the web interface, and
  • the documentation.
Breakdown of space used by each package before and after introducing embed.zip. It is displayed as a treemap and we can see many embedded files replaced by a bigger one.
Breakdown of the space used by each component before (left) and after (right) the introduction of embed.zip.
Embedding these assets into a ZIP archive reduced the size of the Akvorado executable by more than 4 MiB:
$ unzip -p common/embed/data/embed.zip   wc -c   numfmt --to=iec
7.3M
$ ll common/embed/data/embed.zip
-rw-r--r-- 1 bernat users 2.9M Dec  7 17:17 common/embed/data/embed.zip

Performance loss Reading from a compressed archive is not as fast as reading a flat file. A simple benchmark shows it is more than 4 slower. It also allocates some memory.2
goos: linux
goarch: amd64
pkg: akvorado/common/embed
cpu: AMD Ryzen 5 5600X 6-Core Processor
BenchmarkData/compressed-12     2262   526553 ns/op   610 B/op   10 allocs/op
BenchmarkData/uncompressed-12   9482   123175 ns/op     0 B/op    0 allocs/op
Each access to an asset requires a decompression step, as seen in this flame graph:
&#128444; Flame graph when reading data from embed.zip compared to reading data directly
CPU flame graph comparing the time spent on CPU when reading data from embed.zip (left) versus reading data directly (right). Because the Go testing framework executes the benchmark for uncompressed data 4 times more often, it uses the same horizontal space as the benchmark for compressed data. The graph is interactive.
While a ZIP archive has an index to quickly find the requested file, seeking inside a compressed file is currently not possible.3 Therefore, the files from a compressed archive do not implement the io.ReaderAt or io.Seeker interfaces, unlike directly embedded files. This prevents some features, like serving partial files or detecting MIME types when serving files over HTTP.
For Akvorado, this is an acceptable compromise to save a few mebibytes from an executable of almost 100 MiB. Next week, I will continue this futile adventure by explaining how I prevented Go from disabling dead code elimination!

  1. You can safely read multiple files concurrently. However, it does not implement ReadDir() and ReadFile() methods.
  2. You could keep frequently accessed assets in memory. This reduces CPU usage and trades cached memory for resident memory.
  3. SOZip is a profile that enables fast random access in a compressed file. However, Go s archive/zip module does not support it.

2 December 2025

Simon Josefsson: Guix on Trisquel & Ubuntu for Reproducible CI/CD Artifacts

Last week I published Guix on Debian container images that prepared for today s announcement of Guix on Trisquel/Ubuntu container images. I have published images with reasonably modern Guix for Trisquel 11 aramo, Trisquel 12 ecne, Ubuntu 22.04 and Ubuntu 24.04. The Ubuntu images are available for both amd64 and arm64, but unfortunately Trisquel arm64 containers aren t available yet so they are only for amd64. Images for ppc64el and riscv64 are work in progress. The currently supported container names:
registry.gitlab.com/debdistutils/guix/guix-on-dpkg:trisquel11-guix
registry.gitlab.com/debdistutils/guix/guix-on-dpkg:trisquel12-guix
registry.gitlab.com/debdistutils/guix/guix-on-dpkg:ubuntu22.04-guix
registry.gitlab.com/debdistutils/guix/guix-on-dpkg:ubuntu24.04-guix
Or you prefer guix-on-dpkg on Docker Hub:
docker.io/jas4711/guix-on-dpkg:trisquel11-guix
docker.io/jas4711/guix-on-dpkg:trisquel12-guix
docker.io/jas4711/guix-on-dpkg:ubuntu22.04-guix
docker.io/jas4711/guix-on-dpkg:ubuntu24.04-guix
You may use them as follows. See the guix-on-dpkg README for how to start guix-daemon and installing packages.
jas@kaka:~$ podman run -it --hostname guix --rm registry.gitlab.com/debdistutils/guix/guix-on-dpkg:trisquel11-guix
root@guix:/# head -1 /etc/os-release 
NAME="Trisquel GNU/Linux"
root@guix:/# guix describe
  guix 136fc8b
    repository URL: https://gitlab.com/debdistutils/guix/mirror.git
    branch: master
    commit: 136fc8bfe91a64d28b6c54cf8f5930ffe787c16e
root@guix:/# 
You may now be asking yourself: why? Fear not, gentle reader, because having two container images of roughly similar software is a great tool for attempting to build software artifacts reproducible, and comparing the result to spot differences. Obviously. I have been using this pattern to get reproducible tarball artifacts of several software releases for around a year and half, since libntlm 1.8. Let s walk through how to setup a CI/CD pipeline that will build a piece of software, in four different jobs for Trisquel 11/12 and Ubuntu 22.04/24.04. I am in the process of learning Codeberg/Forgejo CI/CD, so I am still using GitLab CI/CD here, but the concepts should be the same regardless of platform. Let s start by defining a job skeleton:
.guile-gnutls: &guile-gnutls
  before_script:
  - /root/.config/guix/current/bin/guix-daemon --version
  - env LC_ALL=C.UTF-8 /root/.config/guix/current/bin/guix-daemon --build-users-group=guixbuild $GUIX_DAEMON_ARGS &
  - GUIX_PROFILE=/root/.config/guix/current; . "$GUIX_PROFILE/etc/profile"
  - type guix
  - guix --version
  - guix describe
  - time guix install --verbosity=0 wget gcc-toolchain autoconf automake libtool gnutls guile pkg-config
  - time apt-get update
  - time apt-get install -y make git texinfo
  - GUIX_PROFILE="/root/.guix-profile"; . "$GUIX_PROFILE/etc/profile"
  script:
  - git clone https://codeberg.org/guile-gnutls/guile-gnutls.git
  - cd guile-gnutls
  - git checkout v5.0.1
  - ./bootstrap
  - ./configure
  - make V=1
  - make V=1 check VERBOSE=t
  - make V=1 dist
  after_script:
  - mkdir -pv out/$CI_JOB_NAME_SLUG/src
  - mv -v guile-gnutls/*-src.tar.* out/$CI_JOB_NAME_SLUG/src/
  - mv -v guile-gnutls/*.tar.* out/$CI_JOB_NAME_SLUG/
  artifacts:
    paths:
    - out/**
This installs some packages, clones guile-gnutls (it could be any project, that s just an example), build it and return tarball artifacts. The artifacts are the git-archive and make dist tarballs. Let s instantiate the skeleton into four jobs, running the Trisquel 11/12 jobs on amd64 and the Ubuntu 22.04/24.04 jobs on arm64 for fun.
guile-gnutls-trisquel11-amd64:
  tags: [ saas-linux-medium-amd64 ]
  image: registry.gitlab.com/debdistutils/guix/guix-on-dpkg:trisquel11-guix
  extends: .guile-gnutls
guile-gnutls-ubuntu22.04-arm64:
  tags: [ saas-linux-medium-arm64 ]
  image: registry.gitlab.com/debdistutils/guix/guix-on-dpkg:ubuntu22.04-guix
  extends: .guile-gnutls
guile-gnutls-trisquel12-amd64:
  tags: [ saas-linux-medium-amd64 ]
  image: registry.gitlab.com/debdistutils/guix/guix-on-dpkg:trisquel12-guix
  extends: .guile-gnutls
guile-gnutls-ubuntu24.04-arm64:
  tags: [ saas-linux-medium-arm64 ]
  image: registry.gitlab.com/debdistutils/guix/guix-on-dpkg:ubuntu24.04-guix
  extends: .guile-gnutls
Running this pipeline will result in artifacts that you want to confirm for reproducibility. Let s add a pipeline job to do the comparison:
guile-gnutls-compare:
  image: alpine:latest
  needs: [ guile-gnutls-trisquel11-amd64,
           guile-gnutls-trisquel12-amd64,
           guile-gnutls-ubuntu22.04-arm64,
           guile-gnutls-ubuntu24.04-arm64 ]
  script:
  - cd out
  - sha256sum */*.tar.* */*/*.tar.*   sort   grep    -- -src.tar.
  - sha256sum */*.tar.* */*/*.tar.*   sort   grep -v -- -src.tar.
  - sha256sum */*.tar.* */*/*.tar.*   sort   uniq -c -w64   sort -rn
  - sha256sum */*.tar.* */*/*.tar.*   grep    -- -src.tar.   sort   uniq -c -w64   grep -v '^      1 '
  - sha256sum */*.tar.* */*/*.tar.*   grep -v -- -src.tar.   sort   uniq -c -w64   grep -v '^      1 '
# Confirm modern git-archive tarball reproducibility
  - cmp guile-gnutls-trisquel12-amd64/src/*.tar.gz guile-gnutls-ubuntu24-04-arm64/src/*.tar.gz
# Confirm old git-archive (export-subst but long git describe) tarball reproducibility
  - cmp guile-gnutls-trisquel11-amd64/src/*.tar.gz guile-gnutls-ubuntu22-04-arm64/src/*.tar.gz
# Confirm 'make dist' generated tarball reproducibility
  - cmp guile-gnutls-trisquel11-amd64/*.tar.gz guile-gnutls-ubuntu22-04-arm64/*.tar.gz
  - cmp guile-gnutls-trisquel12-amd64/*.tar.gz guile-gnutls-ubuntu24-04-arm64/*.tar.gz
  artifacts:
    when: always
    paths:
    - ./out/**
Look how beautiful, almost like ASCII art! The commands print SHA256 checksums of the artifacts, sorted in a couple of ways, and then proceeds to compare relevant artifacts. What would the output of such a run be, you may wonder? You can look for yourself in the guix-on-dpkg pipeline but here is the gist of it:
$ cd out
$ sha256sum */*.tar.* */*/*.tar.*   sort   grep    -- -src.tar.
79bc24143ba083819b36822eacb8f9e15a15a543e1257c53d30204e9ffec7aca  guile-gnutls-trisquel11-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
79bc24143ba083819b36822eacb8f9e15a15a543e1257c53d30204e9ffec7aca  guile-gnutls-ubuntu22-04-arm64/src/guile-gnutls-v5.0.1-src.tar.gz
b190047cee068f6b22a5e8d49ca49a2425ad4593901b9ac8940f8842ba7f164f  guile-gnutls-trisquel12-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
b190047cee068f6b22a5e8d49ca49a2425ad4593901b9ac8940f8842ba7f164f  guile-gnutls-ubuntu24-04-arm64/src/guile-gnutls-v5.0.1-src.tar.gz
$ sha256sum */*.tar.* */*/*.tar.*   sort   grep -v -- -src.tar.
1e8d107ad534b85f30e432d5c98bf599aab5d8db5f996c2530aabe91f203018a  guile-gnutls-trisquel11-amd64/guile-gnutls-5.0.1.tar.gz
1e8d107ad534b85f30e432d5c98bf599aab5d8db5f996c2530aabe91f203018a  guile-gnutls-ubuntu22-04-arm64/guile-gnutls-5.0.1.tar.gz
bc2df2d868f141bca5f3625aa146aa0f24871f6dcf0b48ff497eba3bb5219b84  guile-gnutls-trisquel12-amd64/guile-gnutls-5.0.1.tar.gz
bc2df2d868f141bca5f3625aa146aa0f24871f6dcf0b48ff497eba3bb5219b84  guile-gnutls-ubuntu24-04-arm64/guile-gnutls-5.0.1.tar.gz
$ sha256sum */*.tar.* */*/*.tar.*   sort   uniq -c -w64   sort -rn
      2 bc2df2d868f141bca5f3625aa146aa0f24871f6dcf0b48ff497eba3bb5219b84  guile-gnutls-trisquel12-amd64/guile-gnutls-5.0.1.tar.gz
      2 b190047cee068f6b22a5e8d49ca49a2425ad4593901b9ac8940f8842ba7f164f  guile-gnutls-trisquel12-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
      2 79bc24143ba083819b36822eacb8f9e15a15a543e1257c53d30204e9ffec7aca  guile-gnutls-trisquel11-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
      2 1e8d107ad534b85f30e432d5c98bf599aab5d8db5f996c2530aabe91f203018a  guile-gnutls-trisquel11-amd64/guile-gnutls-5.0.1.tar.gz
$ sha256sum */*.tar.* */*/*.tar.*   grep    -- -src.tar.   sort   uniq -c -w64   grep -v '^      1 '
      2 79bc24143ba083819b36822eacb8f9e15a15a543e1257c53d30204e9ffec7aca  guile-gnutls-trisquel11-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
      2 b190047cee068f6b22a5e8d49ca49a2425ad4593901b9ac8940f8842ba7f164f  guile-gnutls-trisquel12-amd64/src/guile-gnutls-v5.0.1-src.tar.gz
$ sha256sum */*.tar.* */*/*.tar.*   grep -v -- -src.tar.   sort   uniq -c -w64   grep -v '^      1 '
      2 1e8d107ad534b85f30e432d5c98bf599aab5d8db5f996c2530aabe91f203018a  guile-gnutls-trisquel11-amd64/guile-gnutls-5.0.1.tar.gz
      2 bc2df2d868f141bca5f3625aa146aa0f24871f6dcf0b48ff497eba3bb5219b84  guile-gnutls-trisquel12-amd64/guile-gnutls-5.0.1.tar.gz
$ cmp guile-gnutls-trisquel12-amd64/src/*.tar.gz guile-gnutls-ubuntu24-04-arm64/src/*.tar.gz
$ cmp guile-gnutls-trisquel11-amd64/src/*.tar.gz guile-gnutls-ubuntu22-04-arm64/src/*.tar.gz
$ cmp guile-gnutls-trisquel11-amd64/*.tar.gz guile-gnutls-ubuntu22-04-arm64/*.tar.gz
$ cmp guile-gnutls-trisquel12-amd64/*.tar.gz guile-gnutls-ubuntu24-04-arm64/*.tar.gz
That s it for today, but stay tuned for more updates on using Guix in containers, and remember; Happy Hacking!

19 November 2025

Michael Ablassmeier: building SLES 16 vagrant/libvirt images using guestfs tools

SLES 16 has been released. In the past, SUSE offered ready built vagrant images. Unfortunately that s not the case anymore, as with more recent SLES15 releases the official images were gone. In the past, it was possible to clone existing projects on the opensuse build service to build the images by yourself, but i couldn t find any templates for SLES 16. Naturally, there are several ways to build images, and the tooling around involves kiwi-ng, opensuse build service, or packer recipes etc.. (existing packer recipes wont work anymore, as Yast has been replaced by a new installer, called agma). All pretty complicated, So my current take on creating a vagrant image for SLE16 has been the following: Two guestfs-tools that can now be used to modify the created qcow2 image:
 virt-sysprep -a sles16.qcow2
#!/bin/bash
useradd vagrant
mkdir -p /home/vagrant/.ssh/
chmod 0700 /home/vagrant/.ssh/
echo "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6NF8iallvQVp22WDkTkyrtvp9eWW6A8YVr+kz4TjGYe7gHzIw+niNltGEFHzD8+v1I2YJ6oXevct1YeS0o9HZyN1Q9qgCgzUFtdOKLv6IedplqoPkcmF0aYet2PkEDo3MlTBckFXPITAMzF8dJSIF
o9D8HfdOV0IAdx4O7PtixWKn5y2hMNG0zQPyUecp4pzC6kivAIhyfHilFR61RGL+GPXQ2MWZWFYbAGjyiYJnAmCP3NOTd0jMZEnDkbUvxhMmBYSdETk1rRgm+R4LOzFUGaHqHDLKLX+FIPKcF96hrucXzcWyLbIbEgE98OHlnVYCzRdK8jlqm8tehUc9c9W
hQ== vagrant insecure public key" > /home/vagrant/.ssh/authorized_keys
chmod 0600 /home/vagrant/.ssh/authorized_keys
chown -R vagrant:vagrant /home/vagrant/
# apply recommended ssh settings for vagrant boxes
SSHD_CONFIG=/etc/ssh/sshd_config.d/99-vagrant.conf
if [[ ! -d "$(dirname $ SSHD_CONFIG )" ]]; then
    SSHD_CONFIG=/etc/ssh/sshd_config
    # prepend the settings, so that they take precedence
    echo -e "UseDNS no\nGSSAPIAuthentication no\n$(cat $ SSHD_CONFIG )" > $ SSHD_CONFIG 
else
    echo -e "UseDNS no\nGSSAPIAuthentication no" > $ SSHD_CONFIG 
fi
SUDOERS_LINE="vagrant ALL=(ALL) NOPASSWD: ALL"
if [ -d /etc/sudoers.d ]; then
    echo "$SUDOERS_LINE" >  /etc/sudoers.d/vagrant
    visudo -cf /etc/sudoers.d/vagrant
    chmod 0440 /etc/sudoers.d/vagrant
else
    echo "$SUDOERS_LINE" >> /etc/sudoers
    visudo -cf /etc/sudoers
fi
 
mkdir -p /vagrant
chown -R vagrant:vagrant /vagrant
systemctl enable sshd
 virt-customize -a sle16.qcow2 --upload vagrant.sh:/tmp/vagrant.sh
 virt-customize -a sle16.qcow2 --run-command "/tmp/vagrant.sh"
After this, use the create-box.sh from the vagrant-libvirt project to create an box image: https://github.com/vagrant-libvirt/vagrant-libvirt/blob/main/tools/create_box.sh and add the image to your environment:
 create_box.sh sle16.qcow2 sle16.box
 vagrant box add --name my/sles16 test.box
the resulting box is working well within my CI environment as far as i can tell.

13 November 2025

Freexian Collaborators: Debian Contributions: Upstreaming cPython patches, ansible-core autopkgtest robustness and more! (by Anupa Ann Joseph)

Debian Contributions: 2025-10 Contributing to Debian is part of Freexian s mission. This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services.

Upstreaming cPython patches, by Stefano Rivera Python 3.14.0 (final) released in early October, and Stefano uploaded it to Debian unstable. The transition to support 3.14 has begun in Ubuntu, but hasn t started in Debian, yet. While build failures in Debian s non-release ports are typically not a concern for package maintainers, Python is fairly low in the stack. If a new minor version has never successfully been built for a Debian port by the time we start supporting it, it will quickly become a problem for the port. Python 3.14 had been failing to build on two Debian ports architectures (hppa and m68k), but thankfully their porters provided patches. These were applied and uploaded, and Stefano forwarded the hppa one upstream. Getting it into shape for upstream approval took some work, and shook out several other regressions for the Python hppa port. Debugging these on slow hardware takes a while. These two ports aren t successfully autobuilding 3.14 yet (they re both timing out in tests), but they re at least manually buildable, which unblocks the ports. Docutils 0.22 also landed in Debian around this time, and Python needed some work to build its docs with it. The upstream isn t quite comfortable with distros using newer docutils, so there isn t a clear path forward for these patches, yet. The start of the Python 3.15 cycle was also a good time to renew submission attempts on our other outstanding python patches, most importantly multiarch tuples for stable ABI extension filenames.

ansible-core autopkgtest robustness, by Colin Watson The ansible-core package runs its integration tests via autopkgtest. For some time, we ve seen occasional failures in the expect, pip, and template_jinja2_non_native tests that usually go away before anyone has a chance to look into them properly. Colin found that these were blocking an openssh upgrade and so decided to track them down. It turns out that these failures happened exactly when the libpython3.13-stdlib package had different versions in testing and unstable. A setup script removed /usr/lib/python3*/EXTERNALLY-MANAGED in order that pip can install system packages for some of the tests, but if a package shipping that file were ever upgraded then that customization would be undone, and the same setup script removed apt pins in a way that caused problems when autopkgtest was invoked in certain ways. In combination with this, one of the integration tests attempted to disable system apt sources while testing the behaviour of the ansible.builtin.apt module, but it failed to do so comprehensively enough and so that integration test accidentally upgraded the testbed from testing to unstable in the middle of the test. Chaos ensued. Colin fixed this in Debian and contributed the relevant part upstream.

Miscellaneous contributions
  • Carles kept working on the missing-relations (packages which Recommends or Suggests packages that are not available in Debian). He improved the tooling to detect Suggested packages that are not available in Debian because they were removed (or changed names).
  • Carles improved po-debconf-manager to send translations for packages that are not in Salsa. He also improved the UI of the tool (using rich for some of the output).
  • Carles, using po-debconf-manager, reviewed and submitted 38 debconf template translations.
  • Carles created a merge request for distro-tracker to align text and input-field (postponed until distro-tracker uses Bootstrap 5).
  • Rapha l updated gnome-shell-extension-hamster for GNOME 49. It is a GNOME Shell integration for the Hamster time tracker.
  • Rapha l merged a couple of trivial merge requests, but he did not yet find the time to properly review and test the bootstrap 5 related merge requests that are still waiting on salsa.
  • Helmut sent patches for 20 cross build failures.
  • Helmut refactored debvm dropping support for running on bookworm . There are two trixie features improving the operation. mkfs.ext4 can now consume a tar archive to populate the filesystem via libarchive and dash now supports set -o pipefail. Beyond this change in operation, a number of robustness and quality issues have been resolved.
  • Thorsten fixed some bugs in the printing software and uploaded improved versions of brlaser and ifhp. Moreover he uploaded a new upstream version of cups.
  • Emilio updated xorg-server to the latest security release and helped with various transitions.
  • Santiago worked on and reviewed different Salsa CI MR to address some regressions introduced by the move to sbuild+unshare. Those MR included stop adding the salsa-ci user in the build image to the sbuild group, fix the suffix path used by mmdebstrap to create the chroot and update the documentation about how to use aptly repos in another project.
  • Santiago supported the work on the DebConf 26 organisation, particularly helping with an implemented method to count the votes to choose the conference logo.
  • Stefano reviewed Python PEP-725 and PEP-804, which hope to provide a mechanism to declare external (e.g. APT) dependencies in Python packages. Stefano engaged in discussion and provided feedback to the authors.
  • Stefano prepared for Berkeley DB removal in Python.
  • Stefano ported the backend to reverse-depends to Python 3 (yes, it had been running on 2.7) and migrated it to git from bzr.
  • Stefano updated miscellaneous packages, including beautifulsoup4, mkdocs-macros-plugin, python-pipx.
  • Stefano applied an upstream patch to pypy3, fixing an AST Compiler Assertion error.
  • Stefano uploaded an update to distro-info-data, including data for two additional Debian derivatives: eLxr and Devuan.
  • Stefano prepared an update to dh-python, the python packaging tool, merging several contributed patches and resolving some bugs.
  • Colin upgraded OpenSSH to 10.1p1, helped upstream to chase down some regressions, and further upgraded to 10.2p1. This is also now in trixie-backports.
  • Colin fixed several build regressions with Python 3.14, scikit-learn 1.7, and other transitions.
  • Colin investigated a malware report against tini, making use of reproducible builds to help demonstrate that this is highly likely to be a false positive.
  • Anupa prepared questions and collected interview responses from women contributors in Debian to publish the post as part of Ada Lovelace day 2025.

12 October 2025

Dirk Eddelbuettel: RcppSpdlog 0.0.23 on CRAN: New Upstream

Version 0.0.23 of RcppSpdlog arrived on CRAN today (after a slight delay) and has been uploaded to Debian. RcppSpdlog bundles spdlog, a wonderful header-only C++ logging library with all the bells and whistles you would want that was written by Gabi Melman, and also includes fmt by Victor Zverovich. You can learn more at the nice package documention site. This release updates the code to the version 1.16.0 of spdlog which was released yesterday morning, and includes version 1.12.0 of fmt. We also converted the documentation site to now using mkdocs-material to altdoc (plus local style and production tweaks) rather than directly. I updated the package yesterday morning when spdlog was updated. But the passage was delayed for a day at CRAN as their machines still times out hitting the GPL-2 URL from the README.md badge, leading to a human to manually check the log assert the nothingburgerness of it. This timeout does not happen to me locally using the corresponding URL checker package. I pondered this in a r-package-devel thread and may just have to switch to using the R Project URL for the GPL-2 as this is in fact recurrning. The NEWS entry for this release follows.

Changes in RcppSpdlog version 0.0.23 (2025-10-11)
  • Upgraded to upstream release spdlog 1.16.0 (including fmt 12.0)
  • The mkdocs-material documentation site is now generated via altdoc

Courtesy of my CRANberries, there is also a diffstat report detailing changes. More detailed information is on the RcppSpdlog page, or the package documention site.

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.

9 October 2025

Dirk Eddelbuettel: xptr 1.2.0 on CRAN: New(ly Adopted) Package!

Excited to share that xptr is back on CRAN! The xptr package helps to create, check, modify, use, share, external pointer objects. External pointers are used quite extensively throughout R to manage external resources such as datanbase connection objects and alike, and can be very useful to pass pointers to just about any C / C++ data structure around. While described in Writing R Extensions (notably Section 5.13), they can be a little bare-bones and so this package can be useful. It had been created by Randy Lai and maintained by him during 2017 to 2020, but then fell off CRAN. In work with nanoarrow and its clean and minimal Arrow interface xptr came in handy so I adopted it. Several extensions and updates have been added: (compiled) function registration, continuous integration, tests, refreshed and extended documentation as well as a print format extension useful for PyCapsule objects when passing via reticulate. The package documentation site was switched to altdoc driving the most excellent Material for MkDocs framework (providing my first test case of altdoc replacing my older local scripts; I should post some more about that ). The first NEWS entry follow.

Changes in version 1.2.0 (2025-10-03)
  • New maintainer
  • Compiled functions are now registered, .Call() adjusted
  • README.md and DESCRIPTION edited and update
  • Simple unit tests and continunous integration have been added
  • The package documentation site has been recreated using altdoc
  • All manual pages for functions now contain \value sections

For more, see the package page, the git repo or the documentation site.

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.

Charles: How to Build an Incus Buster Image

It s always nice to have container images of Debian releases to test things, run applications or explore a bit without polluting your host machine. From some Brazilian friends (you know who you are ;-), I ve learned the best way to debug a problem or test a fix is spinning up an incus container, getting to it and finding the minimum reproducer. So the combination incus + Debian is something that I m very used to, but the problem is there are no images for Debian ELTS and testing security fixes to see if they actually fix the vulnerability and don t break anything else is very important. Well, the regular images don t materialize out of thin air, right? So we can learn how they are made and try to generate ELTS images in the same way - shouldn t be that difficult, right? Well, kinda ;-) The images available by default in incus come from images.linuxcontainers.org and are built by Jenkins using distrobuilder. If you follow the links, you will find the repository containing the yaml image definitions used by distrobuilder at github.com/lxc/lxc-ci. With a bit of investigation work, a fork, an incus VM with distrobuilder installed and some magic (also called trial and error) I was able to build a buster image! Whooray, but VM and stretch images are still work in progress. Anyway, I wanted to share how you can build your images and document this process so I don t forget, so here we are

Building Instructions We will use an incus trixie VM to perform the build so we don t clutter our own machine.
incus launch images:debian/trixie <instance-name> --vm
Then let s hop into the machine and install the dependencies.
incus shell <instance-name>
And
apt install git distrobuilder
Let s clone the repository with the yaml definition to build a buster container.
git clone --branch support-debian-buster https://github.com/charles2910/lxc-ci.git
# and cd into it
cd lxc-ci
Then all we need is to pass the correct arguments to distrobuilder so it can build the image. It can output the image in the current directory or in a pre-defined place, so let s create an easy place for the images.
mkdir -p /tmp/images/buster/container
# and perform the build
distrobuilder build-incus images/debian.yaml /tmp/images/buster/container/ \
            -o image.architecture=amd64 \
            -o image.release=buster \
            -o image.variant=default  \
            -o source.url="http://archive.debian.org/debian"
It requires a build definition written in yaml format to perform the build. If you are curious, check the images/ subdir. If all worked correctly, you should have two files in your pre-defined target directory. In our case, /tmp/images/buster/container/ contains:
incus.tar.xz  rootfs.squashfs
Let s copy it to our host so we can add the image to our incus server.
incus file pull <instance-name>/tmp/images/buster/container/incus.tar.xz .
incus file pull <instance-name>/tmp/images/buster/container/rootfs.squashfs .
# and import it as debian/10
incus image import incus.tar.xz rootfs.squashfs --alias debian/10
If we are lucky, we can run our Debian buster container now!
incus launch local:debian/10 <debian-buster-instance>
incus shell <debian-buster-instance>
Well, now all that is left is to install Freexian s ELTS package repository and update the image to get a lot of CVE fixes.
apt install --assume-yes wget
wget https://deb.freexian.com/extended-lts/archive-key.gpg -O /etc/apt/trusted.gpg.d/freexian-archive-extended-lts.gpg
cat <<EOF >/etc/apt/sources.list.d/extended-lts.list
deb http://deb.freexian.com/extended-lts buster-lts main contrib non-free
EOF
apt update
apt --assume-yes upgrade

8 October 2025

Dirk Eddelbuettel: RPushbullet 0.3.5: Mostly Maintenance

RPpushbullet demo A new version 0.3.5 of the RPushbullet package arrived on CRAN. It marks the first release in 4 1/2 years for this mature and feature-stable package. RPushbullet interfaces the neat Pushbullet service for inter-device messaging, communication, and more. It lets you easily send (programmatic) alerts like the one to the left to your browser, phone, tablet, or all at once. This releases reflects mostly internal maintenance and updates to the documentation site, to continuous integration, to package metadata, and one code robustitication. See below for more details.

Changes in version 0.3.5 (2025-10-08)
  • URL and BugReports fields have been added to DESCRIPTION
  • The pbPost function deals more robustly with the case of multiple target emails
  • The continuous integration and the README badge have been updated
  • The DESCRIPTION file now use Authors@R
  • The (encrypted) unit test configuration has been adjusted to reflect the current set of active devices
  • The mkdocs-material documentation site is now generated via altdoc

Courtesy of my CRANberries, there is a diffstat report relative to previous release. More detailed information is on the repo where comments and suggestions are welcome.

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.

Sven Hoexter: Backstage Render Markdown in a Collapsible Block

Brief note to maybe spare someone else the trouble. If you want to hide e.g. a huge table in Backstage (techdocs/mkdocs) behind a collapsible element you need the md_in_html extension and use the markdown attribute for it to kick in on the <details> html tag. Add the extension to your mkdocs.yaml:
markdown_extensions:
  - md_in_html
Hide the table in your markdown document in a collapsible element like this:
<details markdown>
<summary>Long Table</summary>
  Foo   Bar  
 - - 
  Fizz   Buzz  
</details>
It's also required to have an empty line between the html tag and starting the markdown part. Rendered for me that way in VSCode, GitHub and Backstage.

3 October 2025

Dirk Eddelbuettel: #053: Adding llvm Snapshots for R Package Testing

Welcome to post 53 in the R4 series. Continuing with posts #51 from Tuesday and #52 from Wednesday and their stated intent of posting some more here is another quick one. Earlier today I helped another package developer who came to the r-package-devel list asking for help with a build error on the Fedora machine at CRAN running recent / development clang. In such situations, the best first step is often to replicate the issue. As I pointed out on the list, the LLVM team behind clang maintains an apt repo at apt.llvm.org/ making it a good resource to add to Debian-based container such as Rocker r-base or the offical r-base (the two are in fact interchangeable, and I take care of both). A small pothole, however, is that the documentation at the top of apt.llvm.org site is a bit stale and behind two aspects that changed on current Debian systems (i.e. unstable/testing as used for r-base). First, apt now prefers files ending in .sources (in a nicer format) and second, it now really requires a key (which is good practice). As it took me a few minutes to regather how to meet both requirements, I reckoned I might as well script this. Et voil the following script does that:
#!/bin/sh

## Update does not hurt but is not strictly needed
#apt update --quiet --quiet
#apt upgrade --yes

## wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key   sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
## or as we are root in container
wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key > /etc/apt/trusted.gpg.d/apt.llvm.org.asc

cat <<EOF >/etc/apt/sources.list.d/llvm-dev.sources
Types: deb
URIs: http://apt.llvm.org/unstable/
# for clang-21 
#   Suites: llvm-toolchain-21
# for current clang
Suites: llvm-toolchain
Components: main
Signed-By: /etc/apt/trusted.gpg.d/apt.llvm.org.asc
EOF

test -d ~/.R   mkdir ~/.R
cat <<EOF >~/.R/Makevars
CLANGVER=-22
# CLANGLIB=-stdlib=libc++
CXX=clang++\$(CLANGVER) \$(CLANGLIB)
CXX11=clang++\$(CLANGVER) \$(CLANGLIB)
CXX14=clang++\$(CLANGVER) \$(CLANGLIB)
CXX17=clang++\$(CLANGVER) \$(CLANGLIB)
CXX20=clang++\$(CLANGVER) \$(CLANGLIB)
CC=clang\$(CLANGVER)
SHLIB_CXXLD=clang++\$(CLANGVER) \$(CLANGLIB)
EOF

apt update
apt install --yes clang-22
Once the script is run, one can test a package (or set of packages) against clang-22 and clang++-22. This may help R package developers. The script is also generic enough for other development communities who can ignore (or comment-out / delete) the bit about ~/.R/Makevars and deploy the compiler differently. Updating the softlink as apt-preferences does is one way and done in many GitHub Actions recipes. As we only need wget here a basic Debian container should work, possibly with the addition of wget. For R users r-base hits a decent sweet spot.

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.

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