Debian Contributions: 2024-09 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.

Pydantic v2, by Colin Watson Pydantic is a useful library for validating data in Python using type hints: Freexian uses it in a number of projects, including Debusine. Its Debian packaging had been stalled at 1.10.17 in testing for some time, partly due to needing to make sure everything else could cope with the breaking changes introduced in 2.x, but mostly due to needing to sort out packaging of its new Rust dependencies. Several other people (notably Alexandre Detiste, Andreas Tille, Drew Parsons, and Timo R hling) had made some good progress on this, but nobody had quite got it over the line and it seemed a bit stuck. Colin upgraded a few Rust libraries to new upstream versions, packaged rust-jiter, and chased various failures in other packages. This eventually allowed getting current versions of both pydantic-core and pydantic into testing. It should now be much easier for us to stay up to date routinely.

Reworking of glib2.0 for cross bootstrap, by Helmut Grohne Simon McVittie (not affiliated with Freexian) earlier restructured the libglib2.0-dev such that it would absorb more functionality and in particular provide tools for working with .gir files. Those tools practically require being run for their host architecture (practically this means running under qemu-user) which is at odds with the requirements of architecture cross bootstrap. The qemu requirement was expressed in package dependencies and also made people unhappy attempting to use libglib2.0-dev for i386 on amd64 without resorting to qemu. The use of qemu in architecture bootstrap is particularly problematic as it tends to not be ready at the time bootstrapping is needed. As a result, Simon proposed and implemented the introduction of a libgio-2.0-dev package providing a subset of libglib2.0-dev that does not require qemu. Packages should continue to use libglib2.0-dev in their Build-Depends unless involved in architecture bootstrap. Helmut reviewed and tested the implementation and integrated the necessary changes into rebootstrap. He also prepared a patch for libverto to use the new package and proposed adding forward compatibility to glib2.0. Helmut continued working on adding cross-exe-wrapper to architecture-properties and implemented autopkgtests later improved by Simon. The cross-exe-wrapper package now provides a generic mechanism to a program on a different architecture by using qemu when needed only. For instance, a dependency on cross-exe-wrapper:i386 provides a i686-linux-gnu-cross-exe-wrapper program that can be used to wrap an ELF executable for the i386 architecture. When installed on amd64 or i386 it will skip installing or running qemu, but for other architectures qemu will be used automatically. This facility can be used to support cross building with targeted use of qemu in cases where running host code is unavoidable as is the case for GObject introspection. This concludes the joint work with Simon and Niels Thykier on glib2.0 and architecture-properties resolving known architecture bootstrap regressions arising from the glib2.0 refactoring earlier this year.

Analyzing binary package metadata, by Helmut Grohne As Guillem Jover (not affiliated with Freexian) continues to work on adding metadata tracking to dpkg, the question arises how this affects existing packages. The dedup.debian.net infrastructure provides an easy playground to answer such questions, so Helmut gathered file metadata from all binary packages in unstable and performed an explorative analysis. Some results include:

• binutils-mipsen uses wrong file ownership
• /usr-merge is not the only cause for aliasing problems in Debian.
  • mediawiki vs vistrails
  • bmake vs ros-mk
  • golang-github-eapache-go-resiliency-dev vs golang-gopkg-eapache-go-resiliency.v1-dev
  • node-markdown-it vs libjs-markdown-it
  • dokuwiki vs php-phpseclib
  • dokuwiki vs php-random-compat

Guillem also performed a cursory analysis and reported other problem categories such as mismatching directory permissions for directories installed by multiple packages and thus gained a better understanding of what consistency checks dpkg can enforce.

Python archive rebuilds, by Stefano Rivera Last month Stefano started to write some tooling to do large-scale rebuilds in debusine, starting with finding packages that had already started to fail to build from source (FTBFS) due to the removal of setup.py test. This month, Stefano did some more rebuilds, starting with experimental versions of dh-python. During the Python 3.12 transition, we had added a dependency on python3-setuptools to dh-python, to ease the transition. Python 3.12 removed distutils from the stdlib, but many packages were expecting it to still be available. Setuptools contains a version of distutils, and dh-python was a convenient place to depend on setuptools for most package builds. This dependency was never meant to be permanent. A rebuild without it resulted in mass-filing about 340 bugs (and around 80 more by mistake). A new feature in Python 3.12, was to have unittest s test runner exit with a non-zero return code, if no tests were run. We added this feature, to be able to detect tests that are not being discovered, by mistake. We are ignoring this failure, as we wouldn t want to suddenly cause hundreds of packages to fail to build, if they have no tests. Stefano did a rebuild to see how many packages were affected, and found that around 1000 were. The Debian Python community has not come to a conclusion on how to move forward with this. As soon as Python 3.13 release candidate 2 was available, Stefano did a rebuild of the Python packages in the archive against it. This was a more complex rebuild than the others, as it had to be done in stages. Many packages need other Python packages at build time, typically to run tests. So transitions like this involve some manual bootstrapping, followed by several rounds of builds. Not all packages could be tested, as not all their dependencies support 3.13 yet. The result was around 100 bugs in packages that need work to support Python 3.13. Many other packages will need additional work to properly support Python 3.13, but being able to build (and run tests) is an important first step.

Miscellaneous contributions

• Carles prepared the update of python-pyaarlo package to a new upstream release.
• Carles worked on updating python-ring-doorbell to a new upstream release. Unfinished, pending to package a new dependency python3-firebase-messaging RFP #1082958 and its dependency python3-http-ece RFP #1083020.
• Carles improved po-debconf-manager. Main new feature is that it can open Salsa merge requests. Aiming for a lightning talk in MiniDebConf Toulouse (November) to be functional end to end and get feedback from the wider public for this proof of concept.
• Carles helped one translator to use po-debconf-manager (added compatibility for bullseye, fixed other issues) and reviewed 17 package templates.
• Colin upgraded the OpenSSH packaging to 9.9p1.
• Colin upgraded the various YubiHSM packages to new upstream versions, enabled more tests, fixed yubihsm-shell build failures on some 32-bit architectures, made yubihsm-shell build reproducibly, and fixed yubihsm-connector to apply udev rules to existing devices when the package is installed. As usual, bookworm-backports is up to date with all these changes.
• Colin fixed quite a bit of fallout from setuptools 72.0.0 removing setup.py test, backported a large upstream patch set to make buildbot work with SQLAlchemy 2.0, and upgraded 25 other Python packages to new upstream versions.
• Enrico worked with Jakob Haufe to get him up to speed for managing sso.debian.org
• Rapha l did remove spam entries in the list of teams on tracker.debian.org (see #1080446), and he applied a few external contributions, fixing a rendering issue and replacing the DDPO link with a more useful alternative. He also gave feedback on a couple of merge requests that required more work. As part of the analysis of the underlying problem, he suggested to the ftpmasters (via #1083068) to auto-reject packages having the too-many-contacts lintian error, and he raised the severity of #1076048 to serious to actually have that 4 year old bug fixed.
• Rapha l uploaded zim and hamster-time-tracker to fix issues with Python 3.12 getting rid of setuptools. He also uploaded a new gnome-shell-extension-hamster to cope with the upcoming transition to GNOME 47.
• Helmut sent seven patches and sponsored one upload for cross build failures.
• Helmut uploaded a Nagios/Icinga plugin check-smart-attributes for monitoring the health of physical disks.
• Helmut collaborated on sbuild reviewing and improving a MR for refactoring the unshare backend.
• Helmut sent a patch fixing coinstallability of gcc-defaults.
• Helmut continued to monitor the evolution of the /usr-move. With more and more key packages such as libvirt or fuse3 fixed. We re moving into the boring long-tail of the transition.
• Helmut proposed updating the meson buildsystem in debhelper to use env2mfile.
• Helmut continued to update patches maintained in rebootstrap. Due to the work on glib2.0 above, rebootstrap moves a lot further, but still fails for any architecture.
• Santiago reviewed some Merge Request in Salsa CI, such as: !478, proposed by Otto to extend the information about how to use additional runners in the pipeline and !518, proposed by Ahmed to add support for Ubuntu images, that will help to test how some debian packages, including the complex MariaDB are built on Ubuntu. Santiago also prepared !545, which will make the reprotest job more consistent with the result seen on reproducible-builds.
• Santiago worked on different tasks related to DebConf 25. Especially he drafted the fundraising brochure (which is almost ready).
• Thorsten Alteholz uploaded package libcupsfilter to fix the autopkgtest and a dependency problem of this package. After package splix was abandoned by upstream and OpenPrinting.org adopted its maintenance, Thorsten uploaded their first release.
• Anupa published posts on the Debian Administrators group in LinkedIn and moderated the group, one of the tasks of the Debian Publicity Team.
• Anupa helped organize DebUtsav 2024. It had over 100 attendees with hand-on sessions on making initial contributions to Linux Kernel, Debian packaging, submitting documentation to Debian wiki and assisting Debian Installations.

• I continued to attend and soemtimes chair Debian kernel team meetings
• For the Debian firmware-nonfree package:
  • I opened the MRs:
    • !105: nvidia-graphics: Add versioned Breaks on initramfs-tools to avoid bug #1076539
    • !107: Update to 20240909; improve orig tarball generation
  • I reviewed the MRs:
    • !79: Improve maintainer scripts of firmware-nonfree
    • !102: Backport firmware-nonfree 20240709-2~bpo12+1 to Bookworm (merged)
    • !103: Add missing symlinks for tas2563 and tas2781 (merged)
    • !106: Update to 20240811 (merged)
  • I merged my own MRs:
    • !104: Update to linux-support-6.10.6
    • !105: nvidia-graphics: Add versioned Breaks on initramfs-tools to avoid bug #1076539
  • I uploaded:
    • version 20240709-2 to unstable
    • version 20240709-2~bpo12+1 to bookworm-backports
  • I respnded to bug reports:
    • #1080492: firmware-nonfree: [i915] With 20240709-2, the external monitors randomly blank for 2-3 seconds (regression) (closed)
• For the kernel-team repository:
  • I reviewed and merged the MR !5: git-format-patch-for-debian: Support for sourcehut
  • I deleted some obsolete text from the kernel upload checklist
• For the Debian linux package:
  • I announced the end of i386 kernel packages
  • I opened or updated the MRs:
    • !741: Fix most reproducibility issues
    • !1182: [x86] ACPI: Enable ACPI_EC_DEBUGFS as module (Closes: #980555)
    • !1188: [arm64] udeb: fix duplicated modules
    • !1199: [i386] Stop building kernel packages
    • !1200: Backport CI support to bullseye
    • !1209: Build fixes for rtla
    • !1213: Build fixes for objtool and rtla
    • !1215: d/rules.real: Try harder to set the locale to C.UTF-8
    • !1218: Clean up udeb configuration
    • !1219: Remove d/b/genorig.py in favour of uscan
    • !1220: [arm64,armhf] udeb: Add all watchdog drivers to kernel-image
  • I reviewed the MRs:
    • !675: [arm64] drivers/usb/host: Enable USB_XHCI_PCI_RENESAS as module (Closes: #1032671)
    • !1732: [x86] linux-cpupower: Add intel-speed-select command (rebased and merged)
    • !1038: debian/rules.real: export LANG = C.UTF-8 for sphinx (closed)
    • !1041: Add -b flag to genorig.py (closed)
    • !1065: Enable UBSAN_BOUNDS and UBSAN_SHIFT (closed)
    • !1166: [amd64] Enable CRYPTO_DEV_IAA_CRYPTO (merged)
    • !1169: [arm64] Add additional kernel with 64k page size
    • !1172: debian/config: add DAMON support for debian kernel (merged)
    • !1177: powerpc: Explicitly disable CRASH_DUMP on 32-bit (merged)
    • !1178: mm: set CONFIG_ZONE_DEVICE=y on most 64-bit architectures, not only amd64 (merged)
    • !1185: riscv64: fix module duplication detected by kernel-wedge starting with version 2.106 (merged)
    • !1186: [arm64] udeb: fix duplicated modules (merged)
    • !1192: [loong64] enable LBT, KVM and para-virt support (merged)
    • !1193: [arm64] Update rk3588 platform support (merged)
    • !1195: [arm64] enable Qualcomm X Elite support (merged)
    • !1196: [arm64] include modules for Rockchip RK3588 (closed)
    • !1198: Revert Make linux-libc-dev provide all cross packages (merged)
    • !1204: [arm64] Enable drivers for K3-AM642 SoC on SolidRun HummingBoard-T
    • !1207: [rt] Update to 6.11-rc5-rt5 (merged)
    • !1208: Support some Wi-Fi 7 devices (merged)
    • !1211: Set CONFIG_I2C=y on alpha and sparc64 (closed)
    • !1214: [loong64] Enable USB EHCI and OHCI host support (merged)
  • I merged my own MRs:
    • !741: Fix most reproducibility issues
    • !1182: [x86] ACPI: Enable ACPI_EC_DEBUGFS as module (Closes: #980555)
    • !1188: [arm64] udeb: fix duplicated modules
    • !1199: [i386] Stop building kernel packages
    • !1200: Backport CI support to bullseye
    • !1209: Build fixes for rtla
    • !1215: d/rules.real: Try harder to set the locale to C.UTF-8
    • !1218: Clean up udeb configuration
  • I uploaded:
    • linux-6.1 versions 6.1.106-3~deb11u1, 6.1.106-3~deb11u2, and 6.1.106-3~deb11u3 to bullseye-security
    • linux version 6.11-1~exp1 to experimental
  • I updated the bullseye-security branch to upstream version 5.10.226
  • I responded to bug reports:
    • #980555: Missing ec_sys module (fixed)
    • #1041484: kernel: hpet_acpi_add: no address or irqs in _CRS (forwarded)
    • #1071468: linux-image-amd64: mess left when kernel installation fails (grub treats the uninstalled kernel as existing) (closed)
    • #1075855: Kernel panic caused by aacraid module prevents normal boot
    • #1076555: linux-image-6.9.9-amd64: boot crash RIP: 0010:kmem_cache_alloc (closed)
    • #1078997: gretap tunnel with checksum enabled: some packets have zero checksum (closed)
    • #1080975: upgrade 6.1.106 to 6.10.6 failed (reassigned)
    • #1081195: devscripts: test-patches KeyError: pae (confirmed)
    • #1082001: linux-image-6.1.0-25-amd64: TOMOYO LSM rejects execveat(AT_EMPTY_PATH) inside chroot (referred upstream)
    • #1081546: new GPU HANG: ecode 12:1:85dffdfb, in Renderer regression in i915 driver since 6.10 kernel upgrade (more info requested)
    • #1081563: Please consider adding the new Xe Graphics driver for Intel GPUs
    • #1081310: Wired ethernet connection disabled.
  • I sent patches upstream:
    • wifi: iwlegacy: Fix field-spanning write warning in il_enqueue_hcmd() which is meant to fix bug #1062421
    • tools/rtla: Fix installation from out-of-tree build
  • I sent a new response to Proposal: Switch to linear git history
• For the Debian nfs-utils package:
  • I reviewed the MRs:
    • !8: Fixes for bugs #849942 and #849608 (closed)
    • !32: d/control: nfs-common: Move python3 to Recommends (merged)
  • I closed my own old bug report #711021: mount.nfs timeout for GETPORT is much too short
• For diffoscope:
  • I commented on issue #100: Excessive memory use when comparing Linux Debian .dbg packages to report that the issue still exists, and to provide a reproducer
  • I commented on issue #342: Gets killed trying to diff very large (~5GB) images which seems like a duplicate of #100
  • I opened the MR !145: Draft: Reduce memory usage by revert to using popen() for diff input and output which fixes #100 but needs work to avoid regressions for other cases
• For the Debian nss-wrapper package, I opened MR !4: Replace wrap-and-sort autopkgtest with a CI job
• For the Debian pam-wrapper package, I opened MR !4: Replace wrap-and-sort autopkgtest with a CI job
• For initramfs-tools:
  • I opened the MR !136: Fix copy_file again; expand documentation and add tests
  • I reviewed the MRs:
    • !66: Add boot script 00_mount_efivarfs mounting efivarfs (closed)
    • !84: Allow providing UDEV_WAIT and ROUNDTTT times in environment variables (closed)
    • !125: hook-functions: Add more modules based on dracut 90kernel-modules (merged)
    • !127: Filter net kernel modules by symbol regexp from dracut
    • !134: add losetup-rootfs-img script: boot from rootfs image files
    • !135: hook-functions: fixes for Qualcomm platforms
  • I responded to bug report #1082647: copy_exec: [regression] ignores trailing slash, installs file as directory name (pending)
• For debian-kernel-handbook:
  • I reviwed the MRs:
    • !7: Add disabling SECURITY_LOCKDOWN_LSM to chapter-common-tasks
    • !8: Disable dwarf toolchain default to really disable debug info (merged)
• I responded (belatedly) to Debian tech-ctte bug #1065416: linux-libc-dev claims to provide linux-libc-dev-ARCH-cross, but it doesn t do that completely

• [unstable] libcupsfilters security update to fix one CVE related to validation of IPP attributes obtained from remote printers
• [unstable] cups-filters security update to fix two CVEs related to validation of IPP attributes obtained from remote printers
• [unstable] cups security update to fix one CVE related to validation of IPP attributes obtained from remote printers
• [DSA 5778-1] prepared package for cups-filters security update to fix two CVEs related to validation of IPP attributes obtained from remote printers
• [DSA 5779-1] prepared package for cups security update to fix one CVE related to validation of IPP attributes obtained from remote printers
• [DLA 3905-1] cups-filters security update to fix two CVEs related to validation of IPP attributes obtained from remote printers
• [DLA 3904-1] cups security update to fix one CVE related to validation of IPP attributes obtained from remote printers
• [DLA 3905-1] cups-filters security update to fix two CVEs related to validation of IPP attributes obtained from remote printers

• [ELA-1186-1]cups-filters security update for two CVEs in Stretch and Buster to fix the IPP attribute related CVEs.
• [ELA-1187-1]cups-filters security update for one CVE in Jessie to fix the IPP attribute related CVEs (the version in Jessie was not affected by the other CVE).

• libcupsfilters to also fix a dependency and autopkgtest issue besides the security fix mentioned above.
• splix for a new upstream version. This package is managed now by OpenPrinting.

• php-spyc
• php-sparkline

• openvlbi
• indi-playerone
• libsbig
• indi-pentax
• indi-sbig
• indi-fishcamp
• indi-inovaplx
• libfishcamp
• libsbig
• libplayeronecamera
• libplayerone
• libahp-gt
• libahp-xc

• pywws

• osmo-libasn1c

• dict-element
• libcds
• libctl
• tntnet
• gnucobol3
• gnucobol4
• meep-mpi-default
• nuspell
• c2go

1. New binsider tool to analyse ELF binaries
2. Unreproducibility of GHC Haskell compiler 95% fixed
3. Mailing list summary
4. Towards a 100% bit-for-bit reproducible OS
5. Two new reproducibility-related academic papers
6. Distribution work
7. diffoscope
8. Other software development
9. Android toolchain core count issue reported
10. New Gradle plugin for reproducibility
11. Website updates
12. Upstream patches
13. Reproducibility testing framework

New binsider tool to analyse ELF binaries Reproducible Builds developer Orhun Parmaks z has announced a fantastic new tool to analyse the contents of ELF binaries. According to the project s README page:

Binsider can perform static and dynamic analysis, inspect strings, examine linked libraries, and perform hexdumps, all within a user-friendly terminal user interface!

More information about Binsider s features and how it works can be found within Binsider s documentation pages.

Unreproducibility of GHC Haskell compiler 95% fixed A seven-year-old bug about the nondeterminism of object code generated by the Glasgow Haskell Compiler (GHC) received a recent update, consisting of Rodrigo Mesquita noting that the issue is:

95% fixed by [merge request] !12680 when -fobject-determinism is enabled. [ ]

The linked merge request has since been merged, and Rodrigo goes on to say that:

After that patch is merged, there are some rarer bugs in both interface file determinism (eg. #25170) and in object determinism (eg. #25269) that need to be taken care of, but the great majority of the work needed to get there should have been merged already. When merged, I think we should close this one in favour of the more specific determinism issues like the two linked above.

Mailing list summary On our mailing list this month:

• Fay Stegerman let everyone know that she started a thread on the Fediverse about the problems caused by unreproducible zlib/deflate compression in .zip and .apk files and later followed up with the results of her subsequent investigation.
• Long-time developer kpcyrd wrote that there has been a recent public discussion on the Arch Linux GitLab [instance] about the challenges and possible opportunities for making the Linux kernel package reproducible , all relating to the CONFIG_MODULE_SIG flag. [ ]
• Bernhard M. Wiedemann followed-up to an in-person conversation at our recent Hamburg 2024 summit on the potential presence for Reproducible Builds in recognised standards. [ ]
• Fay Stegerman also wrote about her worry about the possible repercussions for RB tooling of Debian migrating from zlib to zlib-ng as reproducibility requires identical compressed data streams. [ ]
• Martin Monperrus wrote the list announcing the latest release of maven-lockfile that is designed aid building Maven projects with integrity . [ ]
• Lastly, Bernhard M. Wiedemann wrote about potential role of reproducible builds in combatting silent data corruption, as detailed in a recent Tweet and scholarly paper on faulty CPU cores. [ ]

Towards a 100% bit-for-bit reproducible OS Bernhard M. Wiedemann began writing on journey towards a 100% bit-for-bit reproducible operating system on the openSUSE wiki:

This is a report of Part 1 of my journey: building 100% bit-reproducible packages for every package that makes up [openSUSE s] minimalVM image. This target was chosen as the smallest useful result/artifact. The larger package-sets get, the more disk-space and build-power is required to build/verify all of them.

This work was sponsored by NLnet s NGI Zero fund.

Two new reproducibility-related academic papers Marvin Strangfeld published his bachelor thesis, Reproducibility of Computational Environments for Software Development from RWTH Aachen University. The author offers a more precise theoretical definition of computational environments compared to previous definitions, which can be applied to describe real-world computational environments. Additionally, Marvin provide a definition of reproducibility in computational environments, enabling discussions about the extent to which an environment can be made reproducible. The thesis is available to browse or download in PDF format. In addition, Shenyu Zheng, Bram Adams and Ahmed E. Hassan of Queen s University, ON, Canada have published an article on hermeticity in Bazel-based build systems:

A hermetic build system manages its own build dependencies, isolated from the host file system, thereby securing the build process. Although, in recent years, new artifact-based build technologies like Bazel offer build hermeticity as a core functionality, no empirical study has evaluated how effectively these new build technologies achieve build hermeticity. This paper studies 2,439 non-hermetic build dependency packages of 70 Bazel-using open-source projects by analyzing 150 million Linux system file calls collected in their build processes. We found that none of the studied projects has a completely hermetic build process, largely due to the use of non-hermetic top-level toolchains. [ ]

Distribution work In Debian this month, 14 reviews of Debian packages were added, 12 were updated and 20 were removed, all adding to our knowledge about identified issues. A number of issue types were updated as well. [ ][ ] In addition, Holger opened 4 bugs against the debrebuild component of the devscripts suite of tools. In particular:

• #1081047: Fails to download .dsc file.
• #1081048: Does not work with a proxy.
• #1081050: Fails to create a debrebuild.tar.
• #1081839: Fails with E: mmdebstrap failed to run error.

Last month, an issue was filed to update the Salsa CI pipeline (used by 1,000s of Debian packages) to no longer test for reproducibility with reprotest s build_path variation. Holger Levsen provided a rationale for this change in the issue, which has already been made to the tests being performed by tests.reproducible-builds.org. This month, this issue was closed by Santiago R. R., nicely explaining that build path variation is no longer the default, and, if desired, how developers may enable it again. In openSUSE news, Bernhard M. Wiedemann published another report for that distribution.

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 version 278 to Debian:

• New features:
  • Add a helpful contextual message to the output if comparing Debian .orig tarballs within .dsc files without the ability to fuzzy-match away the leading directory. [ ]
• Bug fixes:
  • Drop removal of calculated os.path.basename from GNU readelf output. [ ]
  • Correctly invert X% similar value and do not emit 100% similar . [ ]
• Misc:
  • Temporarily remove procyon-decompiler from Build-Depends as it was removed from testing (via #1057532). (#1082636)
  • Update copyright years. [ ]

For trydiffoscope, the command-line client for the web-based version of diffoscope, Chris Lamb also:

• Added an explicit python3-setuptools dependency. (#1080825)
• Bumped the Standards-Version to 4.7.0. [ ]

Other software development disorderfs is our FUSE-based filesystem that deliberately introduces non-determinism into system calls to reliably flush out reproducibility issues. This month, version 0.5.11-4 was uploaded to Debian unstable by Holger Levsen making the following changes:

• Replace build-dependency on the obsolete pkg-config package with one on pkgconf, following a Lintian check. [ ]
• Bump Standards-Version field to 4.7.0, with no related changes needed. [ ]

In addition, reprotest is our tool for building the same source code twice in different environments and then checking the binaries produced by each build for any differences. This month, version 0.7.28 was uploaded to Debian unstable by Holger Levsen including a change by Jelle van der Waa to move away from the pipes Python module to shlex, as the former will be removed in Python version 3.13 [ ].

Android toolchain core count issue reported Fay Stegerman reported an issue with the Android toolchain where a part of the build system generates a different classes.dex file (and thus a different .apk) depending on the number of cores available during the build, thereby breaking Reproducible Builds:

We ve rebuilt [tag v3.6.1] multiple times (each time in a fresh container): with 2, 4, 6, 8, and 16 cores available, respectively:

• With 2 and 4 cores we always get an unsigned APK with SHA-256 14763d682c9286ef .
• With 6, 8, and 16 cores we get an unsigned APK with SHA-256 35324ba4c492760 instead.

New Gradle plugin for reproducibility A new plugin for the Gradle build tool for Java has been released. This easily-enabled plugin results in:

reproducibility settings [being] applied to some of Gradle s built-in tasks that should really be the default. Compatible with Java 8 and Gradle 8.3 or later.

Website updates There were a rather substantial number of improvements made to our website this month, including:

• Chris Lamb:
  • Attempt to use GitLab CI to artifact the website; hopefully useful for testing branches. [ ]
  • Correct the linting rule whilst building the website. [ ]
  • Make a number of small changes to Kees post written by Vagrant. [ ][ ][ ]
  • Add the Civil Infrastructure Platform to the Projects page. [ ]
  • Miscellaneous administration of misfiled images. [ ][ ]
• Evangelos Tzaras made a huge number of changes related to the recent Hamburg 2024 summit [ ][ ][ ][ ][ ] as well as proposed an infographic about which question Reproducible Builds is trying to answer.
• Holger Levsen added his two presentations (Reproducible Builds: The First Eleven Years and Preserving *other* build artifacts) to the website. [ ]
• Jelle van der Waa completely modernised the System Images documentation, noting that a lot has changed since 2017(!); ext4, erofs and FAT filesystems can now be made reproducible . [ ]
• Developer RyanSquared replaced the continuous integration test link for Arch Linux on our Projects page with an external instance [ ][ ] as well as updated the documentation to reflect the dependencies required to build the website [ ].
• Vagrant Cascadian pushed a lengthy interview with Linux developer Kees Cook. [ ][ ][ ][ ]

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:

• Bernhard M. Wiedemann:
  • agama-integration-tests (random)
  • contrast (FTBFS-nocheck)
  • cpython (FTBFS-2038)
  • crash (parallelism, race)
  • ghostscript (toolchain date)
  • glycin-loaders (FTBFS -j1)
  • gstreamer-plugins-rs (date, other)
  • kernel-doc/Sphinx (toolchain bug, parallelism/race)
  • kernel (parallelism in BTF)
  • libcamera (random key)
  • libgtop (uname -r)
  • libsamplerate (random temporary directory)
  • lua-luarepl (FTBFS)
  • meson (toolchain)
  • netty (modification time in .a)
  • nvidia-persistenced (date)
  • nvidia-xconfig (date-related issue)
  • obs-build (build-tooling corruption)
  • perl (Perl records kernel version)
  • pinentry (make efl droppable)
  • python-PyGithub (FTBFS 2024-11-25)
  • python-Sphinx (parallelism/race)
  • python-chroma-hnswlib (CPU)
  • python-libcst
  • python-pygraphviz (random timing)
  • python312 (.pyc embeds modification time)
  • python312 (drop .pyc from documentation time)
  • scap-security-guide (date)
  • seahorse (parallelism)
  • subversion (minor Java .jar modification times)
  • xen/acpica (date-related issue in toolchain)
  • xmvn (random)
• Fridrich Strba:
  • ant (jar mtime)
  • xmvn (various fixes)
• Chris Lamb:
  • #1082702 filed against magic-wormhole-transit-relay.
  • #1082706 filed against python-sphobjinv.
  • #1082707 filed against lomiri-content-hub.
  • #1082796 filed against python-mt-940.
  • #1082806 filed against tree-puzzle.
  • #1083053 filed against muon-meson.
• James Addison:
  • guake (fix a parallelism/timing-race build bug)
  • sphobjinv (duplicates fix from Debian bug #1082706)

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 September, a number of changes were made by Holger Levsen, including:

• Debian-related changes:
  • Upgrade the osuosl4 node to Debian trixie in anticipation of running debrebuild and rebuilderd there. [ ][ ][ ]
  • Temporarily mark the osuosl4 node as offline due to ongoing xfs_repair filesystem maintenance. [ ][ ]
  • Do not warn about (very old) broken nodes. [ ]
  • Add the risc64 architecture to the multiarch version skew tests for Debian trixie and sid. [ ][ ][ ]
  • Mark the virt 32,64 b nodes as down. [ ]
• Misc changes:
  • Add support for powercycling OpenStack instances. [ ]
  • Update the fail2ban to ban hosts for 4 weeks in total [ ][ ] and take care to never ban our own Jenkins instance. [ ]

In addition, Vagrant Cascadian recorded a disk failure for the virt32b and virt64b nodes [ ], performed some maintenance of the cbxi4a node [ ][ ] and marked most armhf architecture systems as being back online.

---

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:

• IRC: #reproducible-builds on irc.oftc.net.
• Mastodon: @reproducible_builds@fosstodon.org
• Mailing list: rb-general@lists.reproducible-builds.org
• Twitter: @ReproBuilds

1. Introduction
2. Initial evaluation and adaptation
3. Issues extending Polis and adjusting our goals
4. Creating (a) new frontend(s) for Polis (this article)
5. Current status and roadmap

• a stable cross-domain HTTP API
• a low-level JavaScript library for interacting with the HTTP API
• a high-level library of WebComponents as a framework-neutral way of rapidly building frontends

• the Particiapi server which provides the HTTP API
• the example frontend project which currently contains both the client library and an experimental example frontend built with it

• [1] https://tinyurl.com/22x27vdt
• [2] https://www.youtube.com/watch?v=zFMTJm3vmh0
• [3] https://www.codingfont.com/
• [4] https://www.noemamag.com/nationhood-revisited/
• [5] https://www.youtube.com/watch?v=si9iqF5uTFk
• [6] https://tinyurl.com/y27atm9a
• [7] https://tinyurl.com/2ys4ul3f
• [8] https://tinyurl.com/24zng3pr
• [9] https://www.youtube.com/watch?v=eUvdPHw4Nd0
• [10] https://locusmag.com/2024/07/cory-doctorow-unpersoned/

The Event EuroBSDCon was attended by about 200-250 people, the hardcore of the BSD community! Attendees came from all over, I met Canadians, USAians, Germanians, Belgians and Irelandians amongst other nationalities! The event was at UCD Dublin, which is a gorgeous university campus about 10km south of Dublin proper in Stillorgan. The speaker hotel was a 20 minute walk (at my ~9min/km pace) from the hotel, or a quick bus journey. It was a pleasant walk, through the leafy campus and then along some pretty broad pavements, albeit beside a dual carriageway. The cycle infrastructure was pretty excellent too, but I sadly was unable to lease a city bike and make my way around on 2 wheels - Dublinbikes don t extend that far out the city. Lunch each day was Irish themed food - Saturday was beef stew (a Frenchman asked me what it was called - his only equivalent words were Beef Bourguignon ) and Sunday was Bangers & Mash! The kitchen struggled a bit - food was brought out in bowls in waves, and that ensured there was artificial scarcity that clearly left anxiety for some that they weren t going to be fed! Everyone I met was friendly from the day I arrived, and that set me very much at ease and made the event much more enjoyable - things are better shared with others. Big shout out to dch and Blake Willis for spending a lot of time talking to me over the weekend!

Talks I Attended

Keynote: Evidence based Policy formation in the EU Tom Smyth This talk given by Tom Smyth was an interesting look into his work with EU Policymakers in ensuring fair competition for his small, Irish ISP. It was an enlightening look into the workings of the EU and the various bodies that set, and manage policy. It truly is a complicated beast, but the feeling I left with was that there are people all through the organisation who are desperate to do the right thing for EU citizens at all costs. Sadly none of it is directly applicable to me living in the UK, but I still get to have a say on policy and vote in polls as an Irish citizen abroad.

10(ish) years of FreeBSD/arm64 Andrew Turner I have been a fan of ARM platforms for a long, long time. I had an early ARM Chromebook and have been equal measures excited and frustrated by the raspberry pi since first contact. I tend to find other ARM people at events and this was no exception! It was an interesting view into one person s dedication to making arm64 a platform for FreeBSD, starting out with no documentation or hardware to becoming a first-class platform. It s interesting to see the roadmap and things upcoming too and makes me hopeful for the future of arm64 in various OSes!

1-800-RC(8)-HELP: Dial Into FreeBSD Service Scripts Mastery! Mateusz Piotrowski rc scripts and startup applications scare me a bit. I m better at systemd units than sysvinit scripts, but that isn t really a transferable skill! This was a deep dive into lots of the functionality that FreeBSD s RC offers, and highlighted things that I only thought were limited to Linux s systemd. I am much more aware of what it s capable of now, but I m still scared to take it on! Afterwards I had a great chat in the hallway with Mateusz about our OS s different approaches to this problem and was impressed with the pragmatic view he had on startup, systemd, rc and the future!

Package management without borders. Using Ravenports on multiple BSDs Michael Reim Ports on the BSDs interest me, but I hadn t realised that outside of each major BSD s collection there were other, cross platform ports collections offered. Ravenports is one of these under developments, and it was good to understand the hows, why and what s happenings of the system. Plus, with my hibbian obsession on building other people s software as my own packages, it s interesting to see how others are doing it!

Building a Modern Packet Radio Network using Open Software me I spoke for 45 minutes to share my passion and frustration for amateur radio, packet radio, the law, the technology and what we re doing in the UK Packet network. This was a lot of fun - it felt like I had a busy room, lots of people interested in the stupid stuff I do with technology and I had lots of conversations after the fact about radio, telecoms, networking and at one point was cornered by what I describe as the Erlang Mafia to talk about how they could help!

Hacking - 30 years ago Walter Belgers This unrecorded talk looked at the history of the Dutch hacker scene, and a young group of hackers explorations of the early internet before modern security was a thing. It was exciting, enrapturing, well presented and a great story of a well spent youth in front of computers.

Social By 1730 I was pretty drained so I took myself back to the hotel missing the last talks, had some down time, and got the DART train to the social event at Brewdog. This invovled about an hour s walking and some train time and that was a nice time to reset my head and just watch the world. The train I was on had a particularly interesting feature where when the motors were not loaded (slowdown or coasting) the lights slowly flickered dim-bright-dim. I don t know if this is across the fleet or just this one, but it was fun to pontificate as I looked out the window at South Dublin passing by. The social was good - a few beer tokens (cider in my case, trying to avoid beer-driven hangovers still), some pleasant junk food and plenty of good company to talk to, lots of people wanting to talk about radio and packet to me! Brewdog struggled a bit - both in bar speed (a linear queue formed despite the staff preferring the crowd-around method of queue) and buffet food appeared in somewhat disjointed waves, meaning that people loitered around the food tables and cleared the plates of wings, sliders, fries, onion rings, mac & cheese as they appeared 4-5 plates at a time. Perhaps a few hundred hungry bodies was a bit too much for them to feed at once. They had shuffleboard that was played all night by various groups! I caught the last bus home, which was relatively painless!

Is our software sustainable? Kent Inge Fagerland Simonsen This was an interesting look into reducing the footprint of software to make it a net benefit. Lots of examples of how little changes can barrel up to big, gigawatthour changes when aggregated over the entire installbase of android or iOS!

A Packet s Journey Through the OpenBSD Network Stack Alexander Bluhm This was an analysis of what happens at each stage of networking in OpenBSD and was pretty interesting to see. Lots of it was out my depth, but it s cool to get an explanation and appreciation for various elements of how software handles each packet that arrives and the differences in the ipv4 and ipv6 stack!

FreeBSD at 30 Years: Its Secrets to Success Kirk McKusick This was a great statistical breakdown of FreeBSD since inception, including top committers, why certain parts of the system and community work so well and what has given it staying power compared to some projects on the internet that peter out after just a few years! Kirk s excitement and passion for the project really shone through, and I want to read his similarly titled article in the FreeBSD Journal now!

Building an open native FreeBSD CI system from scratch with lua, C, jails & zfs Dave Cottlehuber Dave spoke pretty excitedly about his work on a CI system using tools that FreeBSD ships with, and introduced me to the integration of C and Lua which I wasn t fully aware of before. Or I was, and my brain forgot it! With my interest in software build this year, it was quite a timely look at how others are thinking of doing things (I am doing similar stuff with zfs!). I look forward to playing with it when it finally is released to the Real World!

Building an Appliance Allan Jude This was an interesting look into the tools that FreeBSD provides which can be used to make immutable, appliance OSes without too much overhead. Fail safe upgrades and boots with ZFS, running approved code with secure boot, factory resetting and more were discussed! I have had thoughts around this in the recent past, so it was good to have some ideas validated, some challenged and gave me food for thought.

Experience as a speaker I really enjoyed being a speaker at the event! I ve spoken at other things before, but this really was a cut above. The event having money to provide me a hotel was a really welcome surprise, and also receiving a gorgeous scarf as a speaker gift was a great surprise (and it has already been worn with the change of temperature here in Scotland this week!). I would definitely consider returning, either as an attendee or as a speaker. The community of attendees were pragmatic, interesting, engaging and welcoming, the organising committee were spot-on in their work making it happen and the whole event, while turning my brain to mush with all the information, was really enjoyable and I left energised and excited by things instead of ground down and tired.

Organization Highlights The hackfest was marked by in-depth discussions and knowledge sharing among Linux contributors, making everyone inspired, informed, and connected to the community. Building on feedback from the previous year, we refined the unconference format to enhance participant preparation and engagement. Structured Agenda and Timeboxes: Each session had a defined scope, time limit (1h20 or 2h10), and began with an introductory talk on the topic.

• Participant-Led Discussions: We pre-selected in-person participants to lead discussions, allowing them to prepare introductions, resources, and scope.
• Transparent Scheduling: The schedule was shared in advance as GitHub issues, encouraging participants to review and prepare for sessions of interest.

Engaging Sessions: The hackfest featured a variety of topics, including presentations and discussions on how participants were addressing specific subjects within their companies.

• No Breakout Rooms, No Overlaps: All participants chose to attend all sessions, eliminating the need for separate breakout rooms. We also adapted run-time schedule to keep everybody involved in the same topics.
• Real-time Updates: We provided notifications and updates through dedicated emails and the event matrix room.

Strengthening Community Connections: The hackfest offered ample opportunities for networking among attendees.

• Social Events: Igalia sponsored coffee breaks, lunches, and a dinner at a local restaurant.
• Museum Visit: Participants enjoyed a sponsored visit to the Museum of Estrela Galicia Beer (MEGA).

Fruitful Discussions and Follow-up The structured agenda and breaks allowed us to cover multiple topics during the hackfest. These discussions have led to new display feature development and improvements, as evidenced by patches, merge requests, and implementations in project repositories and mailing lists. With the KMS color management API taking shape, we discussed refinements and best approaches to cover the variety of color pipeline from different hardware-vendors. We are also investigating techniques for a performant SDR<->HDR content reproduction and reducing latency and power consumption when using the color blocks of the hardware.

Color Management/HDR Color Management and HDR continued to be the hottest topic of the hackfest. We had three sessions dedicated to discuss Color and HDR across Linux Display stack layers.

Color/HDR (Kernel-Level) Harry Wentland (AMD) led this session. Here, kernel Developers shared the Color Management pipeline of AMD, Intel and NVidia. We counted with diagrams and explanations from HW-vendors developers that discussed differences, constraints and paths to fit them into the KMS generic color management properties such as advertising modeset needs, IN\_FORMAT, segmented LUTs, interpolation types, etc. Developers from Qualcomm and ARM also added information regarding their hardware. Upstream work related to this session:

• KMS color management properties (new version - v5);
• IGT Tests;
• drm_info draft support of v4 DRM/KMS plane color properties;
• gamescope draft support of v4 DRM/KMS plane color properties;
• Kwin WIP implementation of DRM/KMS plane color properties.

Color/HDR (Compositor-Level) Sebastian Wick (RedHat) led this session. It started with Sebastian s presentation covering Wayland color protocols and compositor implementation. Also, an explanation of APIs provided by Wayland and how they can be used to achieve better color management for applications and discussions around ICC profiles and color representation metadata. There was also an intensive Q&A about LittleCMS with Marti Maria. Upstream work related to this session:

• Wayland color management protocol;
• Wayland color representation protocol;
• HDR support merged on Mutter;
• Color management protocol on Mutter;
• Color management protocol on GTK.

Color/HDR (Use Cases and Testing) Christopher Cameron (Google) and Melissa Wen (Igalia) led this session. In contrast to the other sessions, here we focused less on implementation and more on brainstorming and reflections of real-world SDR and HDR transformations (use and validation) and gainmaps. Christopher gave a nice presentation explaining HDR gainmap images and how we should think of HDR. This presentation and Q&A were important to put participants at the same page of how to transition between SDR and HDR and somehow emulating HDR. We also discussed on the usage of a kernel background color property. Finally, we discussed a bit about Chamelium and the future of VKMS (future work and maintainership).

Power Savings vs Color/Latency Mario Limonciello (AMD) led this session. Mario gave an introductory presentation about AMD ABM (adaptive backlight management) that is similar to Intel DPST. After some discussions, we agreed on exposing a kernel property for power saving policy. This work was already merged on kernel and the userspace support is under development. Upstream work related to this session:

• Kernel series: Add support for power saving policy property (merged)
• Mutter: issue: support for power saving policy property
• Kwin: MR Draft: backends/drm: add support for the power saving policy property

Strategy for video and gaming use-cases Leo Li (AMD) led this session. Miguel Casas (Google) started this session with a presentation of Overlays in Chrome/OS Video, explaining the main goal of power saving by switching off GPU for accelerated compositing and the challenges of different colorspace/HDR for video on Linux. Then Leo Li presented different strategies for video and gaming and we discussed the userspace need of more detailed feedback mechanisms to understand failures when offloading. Also, creating a debugFS interface came up as a tool for debugging and analysis.

Real-time scheduling and async KMS API Xaver Hugl (KDE/BlueSystems) led this session. Compositor developers have exposed some issues with doing real-time scheduling and async page flips. One is that the Kernel limits the lifetime of realtime threads and if a modeset takes too long, the thread will be killed and thus the compositor as well. Also, simple page flips take longer than expected and drivers should optimize them. Another issue is the lack of feedback to compositors about hardware programming time and commit deadlines (the lastest possible time to commit). This is difficult to predict from drivers, since it varies greatly with the type of properties. For example, color management updates take much longer. In this regard, we discusssed implementing a hw_done callback to timestamp when the hardware programming of the last atomic commit is complete. Also an API to pre-program color pipeline in a kind of A/B scheme. It may not be supported by all drivers, but might be useful in different ways.

VRR/Frame Limit, Display Mux, Display Control, and more and beer We also had sessions to discuss a new KMS API to mitigate headaches on VRR and Frame Limit as different brightness level at different refresh rates, abrupt changes of refresh rates, low frame rate compensation (LFC) and precise timing in VRR more. On Display Control we discussed features missing in the current KMS interface for HDR mode, atomic backlight settings, source-based tone mapping, etc. We also discussed the need of a place where compositor developers can post TODOs to be developed by KMS people. The Content-adaptive Scaling and Sharpening session focused on sharpening and scaling filters. In the Display Mux session, we discussed proposals to expose the capability of dynamic mux switching display signal between discrete and integrated GPUs. In the last session of the 2024 Display Next Hackfest, participants representing different compositors summarized current and future work and built a Linux Display wish list , which includes: improvements to VTTY and HDR switching, better dmabuf API for multi-GPU support, definition of tone mapping, blending and scaling sematics, and wayland protocols for advertising to clients which colorspaces are supported. We closed this session with a status update on feature development by compositors, including but not limited to: plane offloading (from libcamera to output) / HDR video offloading (dma-heaps) / plane-based scrolling for web pages, color management / HDR / ICC profiles support, addressing issues such as flickering when color primaries don t match, etc. After three days of intensive discussions, all in-person participants went to a guided tour at the Museum of Extrela Galicia beer (MEGA), pouring and tasting the most famous local beer.

Feedback and Future Directions Participants provided valuable feedback on the hackfest, including suggestions for future improvements.

• Schedule and Break-time Setup: Having a pre-defined agenda and schedule provided a better balance between long discussions and mental refreshments, preventing the fatigue caused by endless discussions.
• Action Points: Some participants recommended explicitly asking for action points at the end of each session and assigning people to follow-up tasks.
• Remote Participation: Remote attendees appreciated the inclusive setup and opportunities to actively participate in discussions.
• Technical Challenges: There were bandwidth and video streaming issues during some sessions due to the large number of participants.

Thank you for joining the 2024 Display Next Hackfest We can t help but thank the 40 participants, who engaged in-person or virtually on relevant discussions, for a collaborative evolution of the Linux display stack and for building an insightful agenda. A big thank you to the leaders and presenters of the nine sessions: Christopher Cameron (Google), Harry Wentland (AMD), Leo Li (AMD), Mario Limoncello (AMD), Sebastian Wick (RedHat) and Xaver Hugl (KDE/BlueSystems) for the effort in preparing the sessions, explaining the topic and guiding discussions. My acknowledge to the others in-person participants that made such an effort to travel to A Coru a: Alex Goins (NVIDIA), David Turner (Raspberry Pi), Georges Stavracas (Igalia), Joan Torres (SUSE), Liviu Dudau (Arm), Louis Chauvet (Bootlin), Robert Mader (Collabora), Tian Mengge (GravityXR), Victor Jaquez (Igalia) and Victoria Brekenfeld (System76). It was and awesome opportunity to meet you and chat face-to-face. Finally, thanks virtual participants who couldn t make it in person but organized their days to actively participate in each discussion, adding different perspectives and valuable inputs even remotely: Abhinav Kumar (Qualcomm), Chaitanya Borah (Intel), Christopher Braga (Qualcomm), Dor Askayo (Red Hat), Jiri Koten (RedHat), Jonas dahl (Red Hat), Leandro Ribeiro (Collabora), Marti Maria (Little CMS), Marijn Suijten, Mario Kleiner, Martin Stransky (Red Hat), Michel D nzer (Red Hat), Miguel Casas-Sanchez (Google), Mitulkumar Golani (Intel), Naveen Kumar (Intel), Niels De Graef (Red Hat), Pekka Paalanen (Collabora), Pichika Uday Kiran (AMD), Shashank Sharma (AMD), Sriharsha PV (AMD), Simon Ser, Uma Shankar (Intel) and Vikas Korjani (AMD). We look forward to another successful Display Next hackfest, continuing to drive innovation and improvement in the Linux display ecosystem!

Organization Highlights The hackfest was marked by in-depth discussions and knowledge sharing among Linux contributors, making everyone inspired, informed, and connected to the community. Building on feedback from the previous year, we refined the unconference format to enhance participant preparation and engagement. Structured Agenda and Timeboxes: Each session had a defined scope, time limit (1h20 or 2h10), and began with an introductory talk on the topic.

• Participant-Led Discussions: We pre-selected in-person participants to lead discussions, allowing them to prepare introductions, resources, and scope.
• Transparent Scheduling: The schedule was shared in advance as GitHub issues, encouraging participants to review and prepare for sessions of interest.

Engaging Sessions: The hackfest featured a variety of topics, including presentations and discussions on how participants were addressing specific subjects within their companies.

• No Breakout Rooms, No Overlaps: All participants chose to attend all sessions, eliminating the need for separate breakout rooms. We also adapted run-time schedule to keep everybody involved in the same topics.
• Real-time Updates: We provided notifications and updates through dedicated emails and the event matrix room.

Strengthening Community Connections: The hackfest offered ample opportunities for networking among attendees.

• Social Events: Igalia sponsored coffee breaks, lunches, and a dinner at a local restaurant.
• Museum Visit: Participants enjoyed a sponsored visit to the Museum of Estrela Galicia Beer (MEGA).

Fruitful Discussions and Follow-up The structured agenda and breaks allowed us to cover multiple topics during the hackfest. These discussions have led to new display feature development and improvements, as evidenced by patches, merge requests, and implementations in project repositories and mailing lists. With the KMS color management API taking shape, we discussed refinements and best approaches to cover the variety of color pipeline from different hardware-vendors. We are also investigating techniques for a performant SDR<->HDR content reproduction and reducing latency and power consumption when using the color blocks of the hardware.

Color Management/HDR Color Management and HDR continued to be the hottest topic of the hackfest. We had three sessions dedicated to discuss Color and HDR across Linux Display stack layers.

Color/HDR (Kernel-Level) Harry Wentland (AMD) led this session. Here, kernel Developers shared the Color Management pipeline of AMD, Intel and NVidia. We counted with diagrams and explanations from HW-vendors developers that discussed differences, constraints and paths to fit them into the KMS generic color management properties such as advertising modeset needs, IN\_FORMAT, segmented LUTs, interpolation types, etc. Developers from Qualcomm and ARM also added information regarding their hardware. Upstream work related to this session:

• KMS color management properties (new version - v5);
• IGT Tests;
• drm_info draft support of v4 DRM/KMS plane color properties;
• gamescope draft support of v4 DRM/KMS plane color properties;
• Kwin WIP implementation of DRM/KMS plane color properties.

Color/HDR (Compositor-Level) Sebastian Wick (RedHat) led this session. It started with Sebastian s presentation covering Wayland color protocols and compositor implementation. Also, an explanation of APIs provided by Wayland and how they can be used to achieve better color management for applications and discussions around ICC profiles and color representation metadata. There was also an intensive Q&A about LittleCMS with Marti Maria. Upstream work related to this session:

• Wayland color management protocol;
• Wayland color representation protocol;
• HDR support merged on Mutter;
• Color management protocol on Mutter;
• Color management protocol on GTK.

Color/HDR (Use Cases and Testing) Christopher Cameron (Google) and Melissa Wen (Igalia) led this session. In contrast to the other sessions, here we focused less on implementation and more on brainstorming and reflections of real-world SDR and HDR transformations (use and validation) and gainmaps. Christopher gave a nice presentation explaining HDR gainmap images and how we should think of HDR. This presentation and Q&A were important to put participants at the same page of how to transition between SDR and HDR and somehow emulating HDR. We also discussed on the usage of a kernel background color property. Finally, we discussed a bit about Chamelium and the future of VKMS (future work and maintainership).

Power Savings vs Color/Latency Mario Limonciello (AMD) led this session. Mario gave an introductory presentation about AMD ABM (adaptive backlight management) that is similar to Intel DPST. After some discussions, we agreed on exposing a kernel property for power saving policy. This work was already merged on kernel and the userspace support is under development. Upstream work related to this session:

• Kernel series: Add support for power saving policy property (merged)
• Mutter: issue: support for power saving policy property
• Kwin: MR Draft: backends/drm: add support for the power saving policy property

Strategy for video and gaming use-cases Leo Li (AMD) led this session. Miguel Casas (Google) started this session with a presentation of Overlays in Chrome/OS Video, explaining the main goal of power saving by switching off GPU for accelerated compositing and the challenges of different colorspace/HDR for video on Linux. Then Leo Li presented different strategies for video and gaming and we discussed the userspace need of more detailed feedback mechanisms to understand failures when offloading. Also, creating a debugFS interface came up as a tool for debugging and analysis.

Real-time scheduling and async KMS API Xaver Hugl (KDE/BlueSystems) led this session. Compositor developers have exposed some issues with doing real-time scheduling and async page flips. One is that the Kernel limits the lifetime of realtime threads and if a modeset takes too long, the thread will be killed and thus the compositor as well. Also, simple page flips take longer than expected and drivers should optimize them. Another issue is the lack of feedback to compositors about hardware programming time and commit deadlines (the lastest possible time to commit). This is difficult to predict from drivers, since it varies greatly with the type of properties. For example, color management updates take much longer. In this regard, we discusssed implementing a hw_done callback to timestamp when the hardware programming of the last atomic commit is complete. Also an API to pre-program color pipeline in a kind of A/B scheme. It may not be supported by all drivers, but might be useful in different ways.

VRR/Frame Limit, Display Mux, Display Control, and more and beer We also had sessions to discuss a new KMS API to mitigate headaches on VRR and Frame Limit as different brightness level at different refresh rates, abrupt changes of refresh rates, low frame rate compensation (LFC) and precise timing in VRR more. On Display Control we discussed features missing in the current KMS interface for HDR mode, atomic backlight settings, source-based tone mapping, etc. We also discussed the need of a place where compositor developers can post TODOs to be developed by KMS people. The Content-adaptive Scaling and Sharpening session focused on sharpening and scaling filters. In the Display Mux session, we discussed proposals to expose the capability of dynamic mux switching display signal between discrete and integrated GPUs. In the last session of the 2024 Display Next Hackfest, participants representing different compositors summarized current and future work and built a Linux Display wish list , which includes: improvements to VTTY and HDR switching, better dmabuf API for multi-GPU support, definition of tone mapping, blending and scaling sematics, and wayland protocols for advertising to clients which colorspaces are supported. We closed this session with a status update on feature development by compositors, including but not limited to: plane offloading (from libcamera to output) / HDR video offloading (dma-heaps) / plane-based scrolling for web pages, color management / HDR / ICC profiles support, addressing issues such as flickering when color primaries don t match, etc. After three days of intensive discussions, all in-person participants went to a guided tour at the Museum of Extrela Galicia beer (MEGA), pouring and tasting the most famous local beer.

Feedback and Future Directions Participants provided valuable feedback on the hackfest, including suggestions for future improvements.

• Schedule and Break-time Setup: Having a pre-defined agenda and schedule provided a better balance between long discussions and mental refreshments, preventing the fatigue caused by endless discussions.
• Action Points: Some participants recommended explicitly asking for action points at the end of each session and assigning people to follow-up tasks.
• Remote Participation: Remote attendees appreciated the inclusive setup and opportunities to actively participate in discussions.
• Technical Challenges: There were bandwidth and video streaming issues during some sessions due to the large number of participants.

Thank you for joining the 2024 Display Next Hackfest We can t help but thank the 40 participants, who engaged in-person or virtually on relevant discussions, for a collaborative evolution of the Linux display stack and for building an insightful agenda. A big thank you to the leaders and presenters of the nine sessions: Christopher Cameron (Google), Harry Wentland (AMD), Leo Li (AMD), Mario Limoncello (AMD), Sebastian Wick (RedHat) and Xaver Hugl (KDE/BlueSystems) for the effort in preparing the sessions, explaining the topic and guiding discussions. My acknowledge to the others in-person participants that made such an effort to travel to A Coru a: Alex Goins (NVIDIA), David Turner (Raspberry Pi), Georges Stavracas (Igalia), Joan Torres (SUSE), Liviu Dudau (Arm), Louis Chauvet (Bootlin), Robert Mader (Collabora), Tian Mengge (GravityXR), Victor Jaquez (Igalia) and Victoria Brekenfeld (System76). It was and awesome opportunity to meet you and chat face-to-face. Finally, thanks virtual participants who couldn t make it in person but organized their days to actively participate in each discussion, adding different perspectives and valuable inputs even remotely: Abhinav Kumar (Qualcomm), Chaitanya Borah (Intel), Christopher Braga (Qualcomm), Dor Askayo, Jiri Koten (RedHat), Jonas dahl (Red Hat), Leandro Ribeiro (Collabora), Marti Maria (Little CMS), Marijn Suijten, Mario Kleiner, Martin Stransky (Red Hat), Michel D nzer (Red Hat), Miguel Casas-Sanchez (Google), Mitulkumar Golani (Intel), Naveen Kumar (Intel), Niels De Graef (Red Hat), Pekka Paalanen (Collabora), Pichika Uday Kiran (AMD), Shashank Sharma (AMD), Sriharsha PV (AMD), Simon Ser, Uma Shankar (Intel) and Vikas Korjani (AMD). We look forward to another successful Display Next hackfest, continuing to drive innovation and improvement in the Linux display ecosystem!

• Enabling Unified Kernel Image on Debian

Preparing for Key Enrollment Before enrolling our keys, we need to put the device in Secure Boot Setup Mode. Verify the status using the bootctl status command. You should see output similar to the following image:

  sudo ls /efi/loader/keys/chamunda
db.auth  KEK.auth  PK.auth

Signing the Bootloader Sign the systemd-boot bootloader with your new keys:

sbsign --key <path-to db.key> --cert <path-to db.crt> \
   /usr/lib/systemd/boot/efi/systemd-bootx64.efi

Install the signed bootloader using bootctl install. The output should resemble this:

Note

If you encounter warnings about mount options, update your fstab with the umask=0077 option for the EFI partition.

Verify the signature using sbsign --verify:

SecureBootPrivateKey=/path/to/db.key
SecureBootCertificate=/path/to/db.crt

sudo dpkg-reconfigure linux-image-$(uname -r)
# Repeat for other kernel versions if necessary

sudo dpkg-reconfigure linux-image-$(uname -r)
/etc/kernel/postinst.d/dracut:
dracut: Generating /boot/initrd.img-6.10.9-amd64
Updating kernel version 6.10.9-amd64 in systemd-boot...
Signing unsigned original image
Using config file: /etc/kernel/uki.conf
+ sbverify --list /boot/vmlinuz-6.10.9-amd64
+ sbsign --key /home/vasudeva.sk/Documents/personal/secureboot/db.key --cert /home/vasudeva.sk/Documents/personal/secureboot/db.crt /tmp/ukicc7vcxhy --output /tmp/kernel-install.staging.QLeGLn/uki.efi
Wrote signed /tmp/kernel-install.staging.QLeGLn/uki.efi
/etc/kernel/postinst.d/zz-systemd-boot:
Installing kernel version 6.10.9-amd64 in systemd-boot...
Signing unsigned original image
Using config file: /etc/kernel/uki.conf
+ sbverify --list /boot/vmlinuz-6.10.9-amd64
+ sbsign --key /home/vasudeva.sk/Documents/personal/secureboot/db.key --cert /home/vasudeva.sk/Documents/personal/secureboot/db.crt /tmp/ukit7r1hzep --output /tmp/kernel-install.staging.dWVt5s/uki.efi
Wrote signed /tmp/kernel-install.staging.dWVt5s/uki.efi

Enrolling Keys in Firmware Use systemd-boot to enroll your keys:

systemctl reboot --boot-loader-menu=0

Select the enroll option with your hostname in the systemd-boot menu. After key enrollment, the system will reboot into the newly signed kernel. Verify with bootctl:

Real estate value Let s clear this one up first. It s not about real estate value, for most companies. City planners and real estate investors might care, but even if your average company owned their building they d close it in an instant all other things being equal. An unoccupied building costs a lot less to maintain. And plenty of companies rent and would save money even if there s a substantial exit fee.

Occupancy levels That said, once you have anyone in the building the equation changes. If you re having to provide power, heating, internet, security/front desk staff etc, you want to make sure you re getting your money s worth. There s no point heating a building that can seat 100 for only 10 people present. One option is to downsize the building, but that leads to not being able to assign everyone a desk, for example. No one I know likes hot desking. There are also scheduling problems about ensuring there are enough desks for everyone who might turn up on a certain day, and you ve ruled out the option of company/office wide events.

Coexistence builds relationships As a remote worker I wish it wasn t true that most people find it easier to form relationships in person, but it is. Some of this can be worked on with specific teambuilding style events, rather than in office working, but I know plenty of folk who hate those as much as they hate the idea of being in the office. I am lucky in that I work with a bunch of folk who are terminally online, so it s much easier to have those casual conversations even being remote, but I also accept I miss out on some things because I m just not in the office regularly enough. You might not care about this ( I just need to put my head down and code, not talk to people ), but don t discount it as a valid reason why companies might want their workers to be in the office. This often matters even more for folk at the start of their career, where having a bunch of experience folk around to help them learn and figure things out ends up working much better in person (my first job offered to let me go mostly remote when I moved to Norwich, but I said no as I knew I wasn t ready for it yet).

Coexistence allows for unexpected interactions People hate the phrase water cooler chat , and I get that, but it covers the idea of casual conversations that just won t happen the same way when people are remote. I experienced this while running Black Cat; every time Simon and I met up in person we had a bunch of useful conversations even though we were on IRC together normally, and had a VoIP setup that meant we regularly talked too. Equally when I was at Nebulon there were conversations I overheard in the office where I was able to correct a misconception or provide extra context. Some of this can be replicated with the right online chat culture, but I ve found many places end up with folk taking conversations to DMs, or they happen in private channels. It happens more naturally in an office environment.

It s easier for bad managers to manage bad performers Again, this falls into the category of things that shouldn t be true, but are. Remote working has increased the ability for people who want to slack off to do so without being easily detected. Ideally what you want is that these folk, if they fail to perform, are then performance managed out of the organisation. That s hard though, there are (rightly) a bunch of rights workers have (I m writing from a UK perspective) around the procedure that needs to be followed. Managers need organisational support in this to make sure they get it right (and folk are given a chance to improve), which is often lacking.

Summary Look, I get there are strong reasons why offering remote is a great thing from the company perspective, but what I ve tried to outline here is that a return-to-office mandate can have some compelling reasons behind it too. Some of those might be things that wouldn t exist in an ideal world, but unfortunately fixing them is a bigger issue than just changing where folk work from. Not acknowledging that just makes any reaction against office work seem ill-informed, to me.

• AS2697 Education and Research Network
• AS9885 NKN Internet Gateway
• AS23770 Tata Institute of Fundamental Research (used as National Centre for Biological Sciences network)
• AS38021 Network of Indian Institute of Foreign Trade
• AS38620 National Knowledge Network
• AS38872 Indian School of Business
• AS45340 B.M.S College of Engineering
• AS55296 National Institute of Public Finance and Policy
• AS55479 Indian Institute of Technology, Kanpur
• AS55566 Inter University Centre for Astronomy and Astrophysics
• AS55824 NKN Core Network
• AS56056 AMITY-IN
• AS55847 NKN Edge Network
• AS58703 Amrita Vishwa Vidyapeetham
• AS58758 Tata Institute of Fundamental Research (used as Homi Bhabha Centre for Science Education (HBCSE) network)
• AS59163 GLA University
• AS59193 Indian Institute of Technology, Hyderabad
• AS131226 Indian Institute of Technology, Roorkee
• AS131473 SRM University
• AS132423 Indian Institute of Technology, Bombay
• AS132524 Tata Institute of Fundamental Research (used as main campus network)
• AS132749 Indraprastha Institute of Information Technology, Delhi
• AS132780 Indian Institute of Technology, Delhi
• AS132984 Uka Tarsadia University
• AS132785 Shiv Nadar Institution of Eminence Deemed to be University
• AS132995 South Asian University
• AS133002 Indian Institute of Tropical Meteorology
• AS133233 S.N. Bose National Centre for Basic Sciences
• AS133273 Tata Institute of Social Sciences
• AS133308 Indira Gandhi Centre For Atomic Research
• AS133313 Saha Institute of Nuclear Physics
• AS133552 B.M.S. College of Engineering
• AS133723 Institute for Plasma Research
• AS134003 Centre For Cellular And Molecular Platforms
• AS134023 Aligarh Muslim University
• AS134322 Tata Institute of Fundamental Research (used as International Centre for Theoretical Sciences (ICTS) network)
• AS134901 Indian Institute of Science Education And Research
• AS134934 Institute For Stem Cell Biology And Regenerative Medicine
• AS135730 Datta Meghe Institute Of Medical Sciences
• AS135734 Birla Institute of Technology And Science
• AS135835 Sardar Vallabhbhai Patel National Police Academy
• AS136005 Raman Research Institute
• AS136304 Institute of Physics, Bhubaneswar
• AS136470 B.M.S. College of Engineering
• AS136702 Physical Research Laboratory
• AS137136 Indian Agricultural Statistics Research Institute
• AS137282 Kalinga Institute of Industrial Technology
• AS137617 Indian Institute of Management, Ahmedabad
• AS137956 Indian Institute of Technology, Ropar
• AS138155 Jawaharlal Nehru University
• AS138231 Indian Institute of Information Technology, Allahabad
• AS140033 Indian Institute of Technology, Bhilai
• AS140118 Indian Institute of Technology Banaras Hindu University
• AS140192 Indian Institute of Information Technology and Management, Kerala
• AS140200 Panjab University
• AS141270 Indian Institute Of Technology, Indore
• AS141340 Indian Institute Of Technology, Madras
• AS141477 Indira Gandhi National Open University
• AS141478 Director National Institute Of Technology, Calicut
• AS141288 National Institute of Science Education And Research Bhubaneswar
• AS141507 National Institute of Mental Health And Neurosciences
• AS142493 Sri Ramachandra Institute Of Higher Education And Research
• AS147239 Lal Bahadur Shastri National Academy of Administration (LBSNAA)
• AS147258 Dayalbagh Educational Institute
• AS149607 National Forensic Sciences University
• AS151086 Amrita Vishwa Vidyapeetham
• AS152533 National Institute of Technology, Karnataka

• AS132926 Allen Career Institute
• AS141841 Indian Institute of Hardware Technology Limited

• Only 14 (out of 67) networks have/announce IPv6 prefixes.
• Two networks have IX presence; AS132785 Shiv Nadar at Extreme IX Delhi and AS56056 Amity at DE-CIX Delhi.
• TIFR as an organization has 4 ASNs (AS23770, AS58758, AS132524 and AS134322), BMS College of Engineering has 3 (AS45340, AS133552 and AS136470) and Amrita Vishwa Vidyapeetham has 2 (AS58703 and AS151086).
• AS2697, AS9885, AS38620, AS55824 and AS55847 ie Education and Research Network (ERNET) and National Knowledge Network (NKN) form the Indian NREN.
• 43 network have NKN as their upstream, while BSNL comes second as upstream for 21.

• [1] https://etbe.coker.com.au/2024/08/24/wifi-6e-mesh/