Search Results: "dpk"

27 November 2023

Fran ois Marier: Automatically rebooting for kernel updates

I use reboot-notifier on most of my servers to let me know when I need to reboot them for kernel updates since I want to decide exactly when those machines go down. On the other hand, my home backup server has very predictable usage patterns and so I decided to go one step further there and automate these necessary reboots. To do that, I first installed reboot-notifier which puts the following script in /etc/kernel/postinst.d/reboot-notifier to detect when a new kernel was installed:
#!/bin/sh
if [ "$0" = "/etc/kernel/postinst.d/reboot-notifier" ]; then
    DPKG_MAINTSCRIPT_PACKAGE=linux-base
fi
echo "*** System restart required ***" > /var/run/reboot-required
echo "$DPKG_MAINTSCRIPT_PACKAGE" >> /var/run/reboot-required.pkgs
Note that unattended-upgrades puts a similar script in /etc/kernel/postinst.d/unattended-upgrades:
#!/bin/sh
case "$DPKG_MAINTSCRIPT_PACKAGE::$DPKG_MAINTSCRIPT_NAME" in
   linux-image-extra*::postrm)
      exit 0;;
esac
if [ -d /var/run ]; then
    touch /var/run/reboot-required
    if ! grep -q "^$DPKG_MAINTSCRIPT_PACKAGE$" /var/run/reboot-required.pkgs 2> /dev/null ; then
        echo "$DPKG_MAINTSCRIPT_PACKAGE" >> /var/run/reboot-required.pkgs
    fi
fi
and so you only need one of them to be installed since they both write to /var/run/reboot-required. It doesn't hurt to have both of them though. Then I created the following cron job (/etc/cron.daily/reboot-local) to actually reboot the server:
#!/bin/bash
REBOOT_REQUIRED=/var/run/reboot-required
if [ -s $REBOOT_REQUIRED ] ; then
    cat "$REBOOT_REQUIRED"   /usr/bin/mail -s "Rebooting $HOSTNAME" root
    /bin/systemctl reboot
fi
With that in place, my server will send me an email and then automatically reboot itself. This is a work in progress because I'd like to add some checks later on to make sure that no backup is in progress during that time (maybe by looking for active ssh connections?), but it works well enough for now. Feel free to leave a comment if you've got a smarter script you'd like to share.

26 November 2023

Niels Thykier: Providing online reference documentation for debputy

I do not think seasoned Debian contributors quite appreciate how much knowledge we have picked up and internalized. As an example, when I need to look up documentation for debhelper, I generally know which manpage to look in. I suspect most long time contributors would be able to a similar thing (maybe down 2-3 manpages). But new contributors does not have the luxury of years of experience. This problem is by no means unique to debhelper. One thing that debhelper does very well, is that it is hard for users to tell where a addon "starts" and debhelper "ends". It is clear you use addons, but the transition in and out of third party provided tools is generally smooth. This is a sign that things "just work(tm)". Except when it comes to documentation. Here, debhelper's static documentation does not include documentation for third party tooling. If you think from a debhelper maintainer's perspective, this seems obvious. Embedding documentation for all the third-party code would be very hard work, a layer-violation, etc.. But from a user perspective, we should not have to care "who" provides "what". As as user, I want to understand how this works and the more hoops I have to jump through to get that understanding, the more frustrated I will be with the toolstack. With this, I came to the conclusion that the best way to help users and solve the problem of finding the documentation was to provide "online documentation". It should be possible to ask debputy, "What attributes can I use in install-man?" or "What does path-metadata do?". Additionally, the lookup should work the same no matter if debputy provided the feature or some third-party plugin did. In the future, perhaps also other types of documentation such as tutorials or how-to guides. Below, I have some tentative results of my work so far. There are some improvements to be done. Notably, the commands for these documentation features are still treated a "plugin" subcommand features and should probably have its own top level "ask-me-anything" subcommand in the future.
Automatic discard rules Since the introduction of install rules, debputy has included an automatic filter mechanism that prunes out unwanted content. In 0.1.9, these filters have been named "Automatic discard rules" and you can now ask debputy to list them.
$ debputy plugin list automatic-discard-rules
+-----------------------+-------------+
  Name                    Provided By  
+-----------------------+-------------+
  python-cache-files      debputy      
  la-files                debputy      
  backup-files            debputy      
  version-control-paths   debputy      
  gnu-info-dir-file       debputy      
  debian-dir              debputy      
  doxygen-cruft-files     debputy      
+-----------------------+-------------+
For these rules, the provider can both provide a description but also an example of their usage.
$ debputy plugin show automatic-discard-rules la-files
Automatic Discard Rule: la-files
================================
Documentation: Discards any .la files beneath /usr/lib
Example
-------
    /usr/lib/libfoo.la        << Discarded (directly by the rule)
    /usr/lib/libfoo.so.1.0.0
The example is a live example. That is, the provider will provide debputy with a scenario and the expected outcome of that scenario. Here is the concrete code in debputy that registers this example:
api.automatic_discard_rule(
    "la-files",
    _debputy_prune_la_files,
    rule_reference_documentation="Discards any .la files beneath /usr/lib",
    examples=automatic_discard_rule_example(
        "usr/lib/libfoo.la",
        ("usr/lib/libfoo.so.1.0.0", False),
    ),
)
When showing the example, debputy will validate the example matches what the plugin provider intended. Lets say I was to introduce a bug in the code, so that the discard rule no longer worked. Then debputy would start to show the following:
# Output if the code or example is broken
$ debputy plugin show automatic-discard-rules la-files
[...]
Automatic Discard Rule: la-files
================================
Documentation: Discards any .la files beneath /usr/lib
Example
-------
    /usr/lib/libfoo.la        !! INCONSISTENT (code: keep, example: discard)
    /usr/lib/libfoo.so.1.0.0
debputy: warning: The example was inconsistent. Please file a bug against the plugin debputy
Obviously, it would be better if this validation could be added directly as a plugin test, so the CI pipeline would catch it. That is one my personal TODO list. :) One final remark about automatic discard rules before moving on. In 0.1.9, debputy will also list any path automatically discarded by one of these rules in the build output to make sure that the automatic discard rule feature is more discoverable.
Plugable manifest rules like the install rule In the manifest, there are several places where rules can be provided by plugins. To make life easier for users, debputy can now since 0.1.8 list all provided rules:
$ debputy plugin list plugable-manifest-rules
+-------------------------------+------------------------------+-------------+
  Rule Name                       Rule Type                      Provided By  
+-------------------------------+------------------------------+-------------+
  install                         InstallRule                    debputy      
  install-docs                    InstallRule                    debputy      
  install-examples                InstallRule                    debputy      
  install-doc                     InstallRule                    debputy      
  install-example                 InstallRule                    debputy      
  install-man                     InstallRule                    debputy      
  discard                         InstallRule                    debputy      
  move                            TransformationRule             debputy      
  remove                          TransformationRule             debputy      
  [...]                           [...]                          [...]        
  remove                          DpkgMaintscriptHelperCommand   debputy      
  rename                          DpkgMaintscriptHelperCommand   debputy      
  cross-compiling                 ManifestCondition              debputy      
  can-execute-compiled-binaries   ManifestCondition              debputy      
  run-build-time-tests            ManifestCondition              debputy      
  [...]                           [...]                          [...]        
+-------------------------------+------------------------------+-------------+
(Output trimmed a bit for space reasons) And you can then ask debputy to describe any of these rules:
$ debputy plugin show plugable-manifest-rules install
Generic install ( install )
===========================
The generic  install  rule can be used to install arbitrary paths into packages
and is *similar* to how  dh_install  from debhelper works.  It is a two "primary" uses.
  1) The classic "install into directory" similar to the standard  dh_install 
  2) The "install as" similar to  dh-exec 's  foo => bar  feature.
Attributes:
 -  source  (conditional): string
    sources  (conditional): List of string
   A path match ( source ) or a list of path matches ( sources ) defining the
   source path(s) to be installed. [...]
 -  dest-dir  (optional): string
   A path defining the destination *directory*. [...]
 -  into  (optional): string or a list of string
   A path defining the destination *directory*. [...]
 -  as  (optional): string
   A path defining the path to install the source as. [...]
 -  when  (optional): manifest condition (string or mapping of string)
   A condition as defined in [Conditional rules](https://salsa.debian.org/debian/debputy/-/blob/main/MANIFEST-FORMAT.md#Conditional rules).
This rule enforces the following restrictions:
 - The rule must use exactly one of:  source ,  sources 
 - The attribute  as  cannot be used with any of:  dest-dir ,  sources 
[...]
(Output trimmed a bit for space reasons) All the attributes and restrictions are auto-computed by debputy from information provided by the plugin. The associated documentation for each attribute is supplied by the plugin itself, The debputy API validates that all attributes are covered and the documentation does not describe non-existing fields. This ensures that you as a plugin provider never forget to document new attributes when you add them later. The debputy API for manifest rules are not quite stable yet. So currently only debputy provides rules here. However, it is my intention to lift that restriction in the future. I got the idea of supporting online validated examples when I was building this feature. However, sadly, I have not gotten around to supporting it yet.
Manifest variables like PACKAGE I also added a similar documentation feature for manifest variables such as PACKAGE . When I implemented this, I realized listing all manifest variables by default would probably be counter productive to new users. As an example, if you list all variables by default it would include DEB_HOST_MULTIARCH (the most common case) side-by-side with the the much less used DEB_BUILD_MULTIARCH and the even lessor used DEB_TARGET_MULTIARCH variable. Having them side-by-side implies they are of equal importance, which they are not. As an example, the ballpark number of unique packages for which DEB_TARGET_MULTIARCH is useful can be counted on two hands (and maybe two feet if you consider gcc-X distinct from gcc-Y). This is one of the cases, where experience makes us blind. Many of us probably have the "show me everything and I will find what I need" mentality. But that requires experience to be able to pull that off - especially if all alternatives are presented as equals. The cross-building terminology has proven to notoriously match poorly to people's expectation. Therefore, I took a deliberate choice to reduce the list of shown variables by default and in the output explicitly list what filters were active. In the current version of debputy (0.1.9), the listing of manifest-variables look something like this:
$ debputy plugin list manifest-variables
+----------------------------------+----------------------------------------+------+-------------+
  Variable (use via:   NAME  )   Value                                    Flag   Provided by  
+----------------------------------+----------------------------------------+------+-------------+
  DEB_HOST_ARCH                      amd64                                           debputy      
  [... other DEB_HOST_* vars ...]    [...]                                           debputy      
  DEB_HOST_MULTIARCH                 x86_64-linux-gnu                                debputy      
  DEB_SOURCE                         debputy                                         debputy      
  DEB_VERSION                        0.1.8                                           debputy      
  DEB_VERSION_EPOCH_UPSTREAM         0.1.8                                           debputy      
  DEB_VERSION_UPSTREAM               0.1.8                                           debputy      
  DEB_VERSION_UPSTREAM_REVISION      0.1.8                                           debputy      
  PACKAGE                            <package-name>                                  debputy      
  path:BASH_COMPLETION_DIR           /usr/share/bash-completion/completions          debputy      
+----------------------------------+----------------------------------------+------+-------------+
+-----------------------+--------+-------------------------------------------------------+
  Variable type           Value    Option                                                 
+-----------------------+--------+-------------------------------------------------------+
  Token variables         hidden   --show-token-variables OR --show-all-variables         
  Special use variables   hidden   --show-special-case-variables OR --show-all-variables  
+-----------------------+--------+-------------------------------------------------------+
I will probably tweak the concrete listing in the future. Personally, I am considering to provide short-hands variables for some of the DEB_HOST_* variables and then hide the DEB_HOST_* group from the default view as well. Maybe something like ARCH and MULTIARCH, which would default to their DEB_HOST_* counter part. This variable could then have extended documentation that high lights DEB_HOST_<X> as its source and imply that there are special cases for cross-building where you might need DEB_BUILD_<X> or DEB_TARGET_<X>. Speaking of variable documentation, you can also lookup the documentation for a given manifest variable:
$ debputy plugin show manifest-variables path:BASH_COMPLETION_DIR
Variable: path:BASH_COMPLETION_DIR
==================================
Documentation: Directory to install bash completions into
Resolved: /usr/share/bash-completion/completions
Plugin: debputy
This was my update on online reference documentation for debputy. I hope you found it useful. :)
Thanks On a closing note, I would like to thanks Jochen Sprickerhof, Andres Salomon, Paul Gevers for their recent contributions to debputy. Jochen and Paul provided a number of real world cases where debputy would crash or not work, which have now been fixed. Andres and Paul also provided corrections to the documentation.

31 October 2023

Iustin Pop: Raspberry PI OS: upgrading and cross-grading

One of the downsides of running Raspberry PI OS is the fact that - not having the resources of pure Debian - upgrades are not recommended, and cross-grades (migrating between armhf and arm64) is not even mentioned. Is this really true? It is, after all a Debian-based system, so it should in theory be doable. Let s try!

Upgrading The recently announced release based on Debian Bookworm here says:
We have always said that for a major version upgrade, you should re-image your SD card and start again with a clean image. In the past, we have suggested procedures for updating an existing image to the new version, but always with the caveat that we do not recommend it, and you do this at your own risk. This time, because the changes to the underlying architecture are so significant, we are not suggesting any procedure for upgrading a Bullseye image to Bookworm; any attempt to do this will almost certainly end up with a non-booting desktop and data loss. The only way to get Bookworm is either to create an SD card using Raspberry Pi Imager, or to download and flash a Bookworm image from here with your tool of choice.
Which means, it s time to actually try it turns out it s actually trivial, if you use RPIs as headless servers. I had only three issues:
  • if using an initrd, the new initrd-building scripts/hooks are looking for some binaries in /usr/bin, and not in /bin; solution: install manually the usrmerge package, and then re-run dpkg --configure -a;
  • also if using an initrd, the scripts are looking for the kernel config file in /boot/config-$(uname -r), and the raspberry pi kernel package doesn t provide this; workaround: modprobe configs && zcat /proc/config.gz > /boot/config-$(uname -r);
  • and finally, on normal RPI systems, that don t use manual configurations of interfaces in /etc/network/interface, migrating from the previous dhcpcd to NetworkManager will break network connectivity, and require you to log in locally and fix things.
I expect most people to hit only the 3rd, and almost no-one to use initrd on raspberry pi. But, overall, aside from these two issues and a couple of cosmetic ones (login.defs being rewritten from scratch and showing a baffling diff, for example), it was easy. Is it worth doing? Definitely. Had no data loss, and no non-booting system.

Cross-grading (32 bit to 64 bit userland) This one is actually painful. Internet searches go from it s possible, I think to it s definitely not worth trying . Examples: Aside from these, there are a gazillion other posts about switching the kernel to 64 bit. And that s worth doing on its own, but it s only half the way. So, armed with two different systems - a RPI4 4GB and a RPI Zero W2 - I tried to do this. And while it can be done, it takes many hours - first system was about 6 hours, second the same, and a third RPI4 probably took ~3 hours only since I knew the problematic issues. So, what are the steps? Basically:
  • install devscripts, since you will need dget
  • enable new architecture in dpkg: dpkg --add-architecture arm64
  • switch over apt sources to include the 64 bit repos, which are different than the 32 bit ones (Raspberry PI OS did a migration here; normally a single repository has all architectures, of course)
  • downgrade all custom rpi packages/libraries to the standard bookworm/bullseye version, since dpkg won t usually allow a single library package to have different versions (I think it s possible to override, but I didn t bother)
  • install libc for the arm64 arch (this takes some effort, it s actually a set of 3-4 packages)
  • once the above is done, install whiptail:amd64 and rejoice at running a 64-bit binary!
  • then painfully go through sets of packages and migrate the set to arm64:
    • sometimes this work via apt, sometimes you ll need to use dget and dpkg -i
    • make sure you download both the armhf and arm64 versions before doing dpkg -i, since you ll need to rollback some installs
  • at one point, you ll be able to switch over dpkg and apt to arm64, at which point the default architecture flips over; from here, if you ve done it at the right moment, it becomes very easy; you ll probably need an apt install --fix-broken, though, at first
  • and then, finish by replacing all packages with arm64 versions
  • and then, dpkg --remove-architecture armhf, reboot, and profit!
But it s tears and blood to get to that point

Pain point 1: RPI custom versions of packages Since the 32bit armhf architecture is a bit weird - having many variations - it turns out that raspberry pi OS has many packages that are very slightly tweaked to disable a compilation flag or work around build/test failures, or whatnot. Since we talk here about 64-bit capable processors, almost none of these are needed, but they do make life harder since the 64 bit version doesn t have those overrides. So what is needed would be to say downgrade all armhf packages to the version in debian upstream repo , but I couldn t find the right apt pinning incantation to do that. So what I did was to remove the 32bit repos, then use apt-show-versions to see which packages have versions that are no longer in any repo, then downgrade them. There s a further, minor, complication that there were about 3-4 packages with same version but different hash (!), which simply needed apt install --reinstall, I think.

Pain point 2: architecture independent packages There is one very big issue with dpkg in all this story, and the one that makes things very problematic: while you can have a library package installed multiple times for different architectures, as the files live in different paths, a non-library package can only be installed once (usually). For binary packages (arch:any), that is fine. But architecture-independent packages (arch:all) are problematic since usually they depend on a binary package, but they always depend on the default architecture version! Hrmm, and I just realise I don t have logs from this, so I m only ~80% confident. But basically:
  • vim-solarized (arch:all) depends on vim (arch:any)
  • if you replace vim armhf with vim arm64, this will break vim-solarized, until the default architecture becomes arm64
So you need to keep track of which packages apt will de-install, for later re-installation. It is possible that Multi-Arch: foreign solves this, per the debian wiki which says:
Note that even though Architecture: all and Multi-Arch: foreign may look like similar concepts, they are not. The former means that the same binary package can be installed on different architectures. Yet, after installation such packages are treated as if they were native architecture (by definition the architecture of the dpkg package) packages. Thus Architecture: all packages cannot satisfy dependencies from other architectures without being marked Multi-Arch foreign.
It also has warnings about how to properly use this. But, in general, not many packages have it, so it is a problem.

Pain point 3: remove + install vs overwrite It seems that depending on how the solver computes a solution, when migrating a package from 32 to 64 bit, it can choose either to:
  • overwrite in place the package (akin to dpkg -i)
  • remove + install later
The former is OK, the later is not. Or, actually, it might be that apt never can do this, for example (edited for brevity):
# apt install systemd:arm64 --no-install-recommends
The following packages will be REMOVED:
  systemd
The following NEW packages will be installed:
  systemd:arm64
0 upgraded, 1 newly installed, 1 to remove and 35 not upgraded.
Do you want to continue? [Y/n] y
dpkg: systemd: dependency problems, but removing anyway as you requested:
 systemd-sysv depends on systemd.
Removing systemd (247.3-7+deb11u2) ...
systemd is the active init system, please switch to another before removing systemd.
dpkg: error processing package systemd (--remove):
 installed systemd package pre-removal script subprocess returned error exit status 1
dpkg: too many errors, stopping
Errors were encountered while processing:
 systemd
Processing was halted because there were too many errors.
But at the same time, overwrite in place is all good - via dpkg -i from /var/cache/apt/archives. In this case it manifested via a prerm script, in other cases is manifests via dependencies that are no longer satisfied for packages that can t be removed, etc. etc. So you will have to resort to dpkg -i a lot.

Pain point 4: lib- packages that are not lib During the whole process, it is very tempting to just go ahead and install the corresponding arm64 package for all armhf lib package, in one go, since these can coexist. Well, this simple plan is complicated by the fact that some packages are named libfoo-bar, but are actual holding (e.g.) the bar binary for the libfoo package. Examples:
  • libmagic-mgc contains /usr/lib/file/magic.mgc, which conflicts between the 32 and 64 bit versions; of course, it s the exact same file, so this should be an arch:all package, but
  • libpam-modules-bin and liblockfile-bin actually contain binaries (per the -bin suffix)
It s possible to work around all this, but it changes a 1 minute:
# apt install $(dpkg -i   grep ^ii   awk ' print $2 ' grep :amrhf sed -e 's/:armhf/:arm64')
into a 10-20 minutes fight with packages (like most other steps).

Is it worth doing? Compared to the simple bullseye bookworm upgrade, I m not sure about this. The result? Yes, definitely, the system feels - weirdly - much more responsive, logged in over SSH. I guess the arm64 base architecture has some more efficient ops than the lowest denominator armhf , so to say (e.g. there was in the 32 bit version some rpi-custom package with string ops), and thus migrating to 64 bit makes more things faster , but this is subjective so it might be actually not true. But from the point of view of the effort? Unless you like to play with dpkg and apt, and understand how these work and break, I d rather say, migrate to ansible and automate the deployment. It s doable, sure, and by the third system, I got this nailed down pretty well, but it was a lot of time spent. The good aspect is that I did 3 migrations:
  • rpi zero w2: bullseye 32 bit to 64 bit, then bullseye to bookworm
  • rpi 4: bullseye to bookworm, then bookworm 32bit to 64 bit
  • same, again, for a more important system
And all three worked well and no data loss. But I m really glad I have this behind me, I probably wouldn t do a fourth system, even if forced And now, waiting for the RPI 5 to be available See you!

8 October 2023

Niels Thykier: A new Debian package helper: debputy

I have made a new helper for producing Debian packages called debputy. Today, I uploaded it to Debian unstable for the first time. This enables others to migrate their package build using dh +debputy rather than the classic dh. Eventually, I hope to remove dh entirely from this equation, so you only need debputy. But for now, debputy still leverages dh support for managing upstream build systems. The debputy tool takes a radicially different approach to packaging compared to our existing packaging methods by using a single highlevel manifest instead of all the debian/install (etc.) and no hook targets in debian/rules. Here are some of the things that debputy can do or does: There are also some features that debputy does not support at the moment: There are all limitations of the current work in progress. I hope to resolve them all in due time.

Trying debputy With the limitations aside, lets talk about how you would go about migrating a package:
# Assuming here you have already run: apt install dh-debputy
$ git clone https://salsa.debian.org/rra/kstart
[...]
$ cd kstart
# Add a Build-Dependency on dh-sequence-debputy
$ perl -n -i -e \
   'print; print " dh-sequence-debputy,\n" if m/debhelper-compat/;' \
    debian/control
$ debputy migrate-from-dh --apply-changes
debputy: info: Loading plugin debputy (version: archive/debian/4.3-1) ...
debputy: info: Verifying the generating manifest
debputy: info: Updated manifest debian/debputy.manifest
debputy: info: Removals:
debputy: info:   rm -f "./debian/docs"
debputy: info:   rm -f "./debian/examples"
debputy: info: Migrations performed successfully
debputy: info: Remember to validate the resulting binary packages after rebuilding with debputy
$ cat debian/debputy.manifest 
manifest-version: '0.1'
installations:
- install-docs:
    sources:
    - NEWS
    - README
    - TODO
- install-examples:
    source: examples/krenew-agent
$ git add debian/debputy.manifest
$ git commit --signoff -am"Migrate to debputy"
# Run build tool of choice to verify the output.
This is of course a specific example that works out of the box. If you were to try this on debianutils (from git), the output would look something like this:
$ debputy migrate-from-dh
debputy: info: Loading plugin debputy (version: 5.13-13-g9836721) ...
debputy: error: Unable to migrate automatically due to missing features in debputy.
  * The "debian/triggers" debhelper config file (used by dh_installdeb is currently not supported by debputy.
Use --acceptable-migration-issues=[...] to convert this into a warning [...]
And indeed, debianutils requires at least 4 debhelper features beyond what debputy can support at the moment (all related to maintscripts and triggers).

Rapid feedback Rapid feedback cycles are important for keeping developers engaged in their work. The debputy tool provides the following features to enable rapid feedback.

Immediate manifest validation It would be absolutely horrible if you had to do a full-rebuild only to realize you got the manifest syntax wrong. Therefore, debputy has a check-manifest command that checks the manifest for syntactical and semantic issues.
$ cat debian/debputy.manifest
manifest-version: '0.1'
installations:
- install-docs:
    sources:
    - GETTING-STARTED-WITH-dh-debputy.md
    - MANIFEST-FORMAT.md
    - MIGRATING-A-DH-PLUGIN.md
$ debputy check-manifest
debputy: info: Loading plugin debputy (version: 0.1.7-1-gf34bd66) ...
debputy: info: No errors detected.
$ cat <<EOF >> debian/debputy.manifest
- install:
    sourced: foo
    as: usr/bin/foo
EOF
# Did I typo anything?
$ debputy check-manifest
debputy: info: Loading plugin debputy (version: 0.1.7-2-g4ef8c2f) ...
debputy: warning: Possible typo: The key "sourced" at "installations[1].install" should probably have been 'source'
debputy: error: Unknown keys " 'sourced' " at installations[1].install".  Keys that could be used here are: sources, when, dest-dir, source, into.
debputy: info: Loading plugin debputy (version: 0.1.7-2-g4ef8c2f) ...
$ sed -i s/sourced:/source:/ debian/debputy.manifest
$ debputy check-manifest
debputy: info: Loading plugin debputy (version: 0.1.7-2-g4ef8c2f) ...
debputy: info: No errors detected.
The debputy check-manifest command is limited to the manifest itself and does not warn about foo not existing as it could be produced as apart of the upstream build system. Therefore, there are still issues that can only be detected at package build time. But where debputy can reliably give you immediate feedback, it will do so.

Idempotence: Clean re-runs of dh_debputy without clean/rebuild If you read the fine print of many debhelper commands, you may see the following note their manpage:
This command is not idempotent. dh_prep(1) should be called between invocations of this command Manpage of an anonymous debhelper tool
What this usually means, is that if you run the command twice, you will get its maintscript change (etc.) twice in the final deb. This fits into our single-use clean throw-away chroot builds on the buildds and CI as well as dpkg-buildpackage s no-clean (-nc) option. Single-use throw-away chroots are not very helpful for debugging though, so I rarely use them when doing the majority of my packaging work as I do not want to wait for the chroot initialization (including installing of build-depends). But even then, I have found that dpkg-buildpackage -nc has been useless for me in many cases as I am stuck between two options:
  • With -nc, you often still interact with the upstream build system. As an example, debhelper will do a dh_prep followed by dh_auto_install, so now we are waiting for upstream s install target to run again. What should have taken seconds now easily take 0.5-1 minute extra per attempt.
  • If you want to by-pass this, you have to manually call the helpers needed (in correct order) and every run accumulates cruft from previous runs to the point that cruft drowns out the actual change you want to see. Also, I am rarely in the mood to play human dh, when I am debugging an issue that I failed to fix in my first, second and third try.
As you can probably tell, neither option has worked that well for me. But with dh_debputy, I have made it a goal that it will not self-taint the final output. If dh_debputy fails, you should be able to tweak the manifest and re-run dh_debputy with the same arguments.
  • No waiting for dpkg-buildpackage -nc nor anything implied by that.
  • No self-tainting of the final deb. The result you get, is the result you would have gotten if the previous dh_debputy run never happened.
  • Because dh_debputy produces the final result, I do not have to run multiple tools in the right order.
Obviously, this is currently a lot easier, because debputy is not involved in the upstream build system at all. If this feature is useful to you, please do let me know and I will try to preserve it as debputy progresses in features.

Packager provided files On a different topic, have you ever wondered what kind of files you can place into the debian directory that debhelper automatically picks up or reacts too? I do not have an answer to that beyond it is over 80 files and that as the maintainer of debhelper, I am not willing to manually maintain such a list manually. However, I do know what the answer is in debputy, because I can just ask debputy:
$ debputy plugin list packager-provided-files
+-----------------------------+---------------------------------------------[...]
  Stem                          Installed As                                [...]
+-----------------------------+---------------------------------------------[...]
  NEWS                          /usr/share/doc/ name /NEWS.Debian           [...]
  README.Debian                 /usr/share/doc/ name /README.Debian         [...]
  TODO                          /usr/share/doc/ name /TODO.Debian           [...]
  bug-control                   /usr/share/bug/ name /control               [...]
  bug-presubj                   /usr/share/bug/ name /presubj               [...]
  bug-script                    /usr/share/bug/ name /script                [...]
  changelog                     /usr/share/doc/ name /changelog.Debian      [...]
  copyright                     /usr/share/doc/ name /copyright             [...]
[...]
This will list all file types (Stem column) that debputy knows about and it accounts for any plugin that debputy can find. Note to be deterministic, debputy will not auto-load plugins that have not been explicitly requested during package builds. So this list could list files that are available but not active for your current package. Note the output is not intended to be machine readable. That may come in later version. Feel free to chime in if you have a concrete use-case.

Take it for a spin As I started this blog post with, debputy is now available in unstable. I hope you will take it for a spin on some of your simpler packages and provide feedback on it.  For documentation, please have a look at: Thanks for considering PS: My deepest respect to the fakeroot maintainers. That game of whack-a-mole is not something I would have been willing to maintain. I think fakeroot is like the Python GIL in the sense that it has been important in getting Debian to where it is today. But at the same time, I feel it is time to let go of the crutch and find a proper solution.

7 October 2023

Andrew Cater: Point release weekend for Debian: two releases this weekend: 202311071653

Over in Cambridge with RattusRattus, Sledge, egw and Isy. Andy is very kindly putting us up.

We're almost all of the way through testing 12.2 and some of the way through testing 11.8.

It's a LONG day - heads down into laptops and relatively quiet - I think we're all tired and we've a way to go yet.


6 October 2023

Emanuele Rocca: Custom Debian Installer and Kernel on a USB stick

There are many valid reasons to create a custom Debian Installer image. You may need to pass some special arguments to the kernel, use a different GRUB version, automate the installation by means of preseeding, use a custom kernel, or modify the installer itself.
If you have a EFI system, which is probably the case in 2023, there is no need to learn complex procedures in order to create a custom Debian Installer stick.
The source of many frustrations is that the ISO format for CDs/DVDs is read-only, but you can just create a VFAT filesystem on a USB stick, copy all ISO contents onto the stick itself, and modify things at will.

Create a writable USB stick
First create a FAT32 filesystem on the removable device and mount it. The device is sdX in the example.
$ sudo parted --script /dev/sdX mklabel msdos
$ sudo parted --script /dev/sdX mkpart primary fat32 0% 100%
$ sudo mkfs.vfat /dev/sdX1
$ sudo mount /dev/sdX1 /mnt/data/
Then copy to the USB stick the installer ISO you would like to modify, debian-testing-amd64-netinst.iso here.
$ sudo kpartx -v -a debian-testing-amd64-netinst.iso
# Mount the first partition on the ISO and copy its contents to the stick
$ sudo mount /dev/mapper/loop0p1 /mnt/cdrom/
$ sudo rsync -av /mnt/cdrom/ /mnt/data/
$ sudo umount /mnt/cdrom
# Same story with the second partition on the ISO
$ sudo mount /dev/mapper/loop0p2 /mnt/cdrom/
$ sudo rsync -av /mnt/cdrom/ /mnt/data/
$ sudo umount /mnt/cdrom
$ sudo kpartx -d debian-testing-amd64-netinst.iso
$ sudo umount /mnt/data
Now try booting from the USB stick just to verify that everything went well and we can start customizing the image.

Boot loader, preseeding, installer hacks
The easiest things we can change now are the shim, GRUB, and GRUB s configuration. The USB stick contains the shim under /EFI/boot/bootx64.efi, while GRUB is at /EFI/boot/grubx64.efi. This means that if you want to test a different shim / GRUB version, you just replace the relevant files. That s it. Take for example /usr/lib/grub/x86_64-efi/monolithic/grubx64.efi from the package grub-efi-amd64-bin, or the signed version from grub-efi-amd64-signed and copy them under /EFI/boot/grubx64.efi. Or perhaps you want to try out systemd-boot? Then take /usr/lib/systemd/boot/efi/systemd-bootx64.efi from the package systemd-boot-efi, copy it to /EFI/boot/bootx64.efi and you re good to go. Figuring out the right systemd-boot configuration needed to start the Installer is left as an exercise.
By editing /boot/grub/grub.cfg you can pass arbitrary arguments to the kernel and the Installer itself. See the official Installation Guide for a comprehensive list of boot parameters.
One very commong thing to do is automating the installation using a preseed file. Add the following to the kernel command line: preseed/file=/cdrom/preseed.cfg and create a /preseed.cfg file on the USB stick. As a little example:
d-i time/zone select Europe/Rome
d-i passwd/root-password this-is-the-root-password
d-i passwd/root-password-again this-is-the-root-password
d-i passwd/user-fullname string Emanuele Rocca
d-i passwd/username string ema
d-i passwd/user-password password lol-haha-uh
d-i passwd/user-password-again password lol-haha-uh
d-i apt-setup/no_mirror boolean true
d-i popularity-contest/participate boolean true
tasksel tasksel/first multiselect standard
See Steve McIntyre s awesome page with the full list of available settings and their description: https://preseed.einval.com/debian-preseed/.
Two noteworthy settings are early_command and late_command. They can be used to execute arbitrary commands and provide thus extreme flexibility! You can go as far as replacing parts of the installer with a sed command, or maybe wgetting an entirely different file. This is a fairly easy way to test minor Installer patches. As an example, I ve once used this to test a patch to grub-installer:
d-i partman/early_command string wget https://people.debian.org/~ema/grub-installer-1035085-1 -O /usr/bin/grub-installer
Finally, the initrd contains all early stages of the installer. It s easy to unpack it, modify whatever component you like, and repack it. Say you want to change a given udev rule:
$ mkdir /tmp/new-initrd
$ cd /tmp/new-initrd
$ zstdcat /mnt/data/install.a64/initrd.gz   sudo cpio -id
$ vi lib/udev/rules.d/60-block.rules
$ find .   cpio -o -H newc   zstd --stdout > /mnt/data/install.a64/initrd.gz

Custom udebs
From a basic architectural standpoint the Debian Installer can be seen as an initrd that loads a series of special Debian packages called udebs. In the previous section we have seen how to (ab)use early_command to replace one of the scripts used by the Installer, namely grub-installer. It turns out that such script is installed by a udeb, so let s do things right and build a new Installer ISO with our custom grub udeb.
Fetch the code for the grub-installer udeb, make your changes and build it with a classic dpkg-buildpackage -rfakeroot.
Then get the Installer code and install all dependencies:
$ git clone https://salsa.debian.org/installer-team/debian-installer/
$ cd debian-installer/
$ sudo apt build-dep .
Now add the grub-installer udeb to the localudebs directory and create a new netboot image:
$ cp /path/to/grub-installer_1.198_arm64.udeb build/localudebs/
$ cd build
$ fakeroot make clean_netboot build_netboot
Give it some time, soon enough you ll have a brand new ISO to test under dest/netboot/mini.iso.

Custom kernel
Perhaps there s a kernel configuration option you need to enable, or maybe you need a more recent kernel version than what is available in sid.
The Debian Linux Kernel Handbook has all the details for how to do things properly, but here s a quick example.
Get the Debian kernel packaging from salsa and generate the upstream tarball:
$ git clone https://salsa.debian.org/kernel-team/linux/
$ ./debian/bin/genorig.py https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
For RC kernels use the repo from Linus instead of linux-stable.
Now do your thing, for instance change a config setting by editing debian/config/amd64/config. Don t worry about where you put it in the file, there s a tool from https://salsa.debian.org/kernel-team/kernel-team to fix that:
$ /path/to/kernel-team/utils/kconfigeditor2/process.py .
Now build your kernel:
$ export MAKEFLAGS=-j$(nproc)
$ export DEB_BUILD_PROFILES='pkg.linux.nokerneldbg pkg.linux.nokerneldbginfo pkg.linux.notools nodoc'
$ debian/rules orig
$ debian/rules debian/control
$ dpkg-buildpackage -b -nc -uc
After some time, if everything went well, you should get a bunch of .deb files as well as a .changes file, linux_6.6~rc3-1~exp1_arm64.changes here. To generate the udebs used by the Installer you need to first get a linux-signed .dsc file, and then build it with sbuild in this example:
$ /path/to/kernel-team/scripts/debian-test-sign linux_6.6~rc3-1~exp1_arm64.changes
$ sbuild --dist=unstable --extra-package=$PWD linux-signed-arm64_6.6~rc3+1~exp1.dsc
Excellent, now you should have a ton of .udebs. To build a custom installer image with this kernel, copy them all under debian-installer/build/localudebs/ and then run fakeroot make clean_netboot build_netboot as described in the previous section. In case you are trying to use a different kernel version from what is currently in sid, you will have to install the linux-image package on the system building the ISO, and change LINUX_KERNEL_ABI in build/config/common. The linux-image dependency in debian/control probably needs to be tweaked as well.
That s it, the new Installer ISO should boot with your custom kernel!
There is going to be another minor obstacle though, as anna will complain that your new kernel cannot be found in the archive. Copy the kernel udebs you have built onto a vfat formatted USB stick, switch to a terminal, and install them all with udpkg:
~ # udpkg -i *.udeb
Now the installation should proceed smoothly.

3 October 2023

Bastian Blank: Introducing uploads to Debian by git tag

Several years ago, several people proposed a mechanism to upload packages to Debian just by doing "git tag" and "git push". Two not too long discussions on debian-devel (first and second) did not end with an agreement how this mechanism could work.1 The central problem was the ability to properly trace uploads back to the ones who authorised it. Now, several years later and after re-reading those e-mail threads, I again was stopped at the question: can we do this? Yes, it would not be just "git tag", but could we do with close enough? I have some rudimentary code ready to actually do uploads from the CI. However the list of caveats are currently pretty long. Yes, it works in principle. It is still disabled here, because in practice it does not yet work. Problems with this setup So what are the problems? It requires the git tags to include the both signed files for a successful source upload. This is solved by a new tool that could be a git sub-command. It just creates the source package, signs it and adds the signed file describing the upload (the .dsc and .changes file) to the tag to be pushed. The CI then extracts the signed files from the tag message and does it's work as normal. It requires a sufficiently reproducible build for source packages. Right now it is only known to work with the special 3.0 (gitarchive) source format, but even that requires the latest version of this format. No idea if it is possible to use others, like 3.0 (quilt) for this purpose. The shared GitLab runner provides by Salsa do not allow ftp access to the outside. But Debian still uses ftp to do uploads. At least if you don't want to share your ssh key, which can't be restricted to uploads only, but ssh would not work either. And as the current host for those builds, the Google Cloud Platform, does not provide connection tracking support for ftp, there is no easy way to allow that without just allowing everything. So we have no way to currently actually perform uploads from this platform. Further work As this is code running in a CI under the control of the developer, we can easily do other workflows. Some teams do workflows that do tags after acceptance into the Debian archive. Or they don't use tags at all. With some other markers, like variables or branch names, this support can be expanded easily. Unrelated to this task here, we might want to think about tying the .changes files for uploads to the target archive. As this code makes all of them readily available in form of tag message, replaying them into possible other archives might be more of a concern now. Conclusion So to come back to the question, yes we can. We can prepare uploads using our CI in a way that they would be accepted into the Debian archive. It just needs some more work on infrastructure.

  1. Here I have to admit that, after reading it again, I'm not really proud of my own behaviour and have to apologise.

26 September 2023

Ravi Dwivedi: Fixing keymaps in Chromebook Running Debian Bookworm

I recently bought an HP Chromebook from Abhas who had already flashed coreboot in it. I ran a fresh installation of Debian 12 (Bookworm) on it with KDE Plasma. Right after installation, the Wi-Fi and bluetooth were working, but I was facing two issues: So I asked my friend Alper for help on fixing the same as he has some experience with Chromebooks. Thanks a lot Alper for the help. I am documenting our steps here for helping others who are facing this issue. Note: This works in X11. For wayland, the steps might differ. To set system-wide keyboard configuration on Debian systems:
$ sudo dpkg-reconfigure keyboard-configuration
Choose Chromebook as the Keyboard Model . Each DE should default to the system configuration, but might need its own configuration which would similarly be available in their GUI tools. But you can check and set it manually from the command line, for example as in this thread. To check the keyboard model Xorg-based DEs:
$ setxkbmap -print -query   grep model:
model:  pc104
To change it temporarily, until a reboot:
$ setxkbmap -model chromebook
If it s not there in KDE settings that would be a bug, To change it persistently for KDE:
$ cat >>.config/kxkbrc <<EOF
[Layout]
Model=chromebook
EOF
This thread was helpful.

Ravi Dwivedi: Fixing audio and keymaps in Chromebook Running Debian Bookworm

I recently bought an HP Chromebook from Abhas who had already flashed coreboot in it. I ran a fresh installation of Debian 12 (Bookworm) on it with KDE Plasma. Right after installation, the Wi-Fi and bluetooth were working, but I was facing two issues:

Fixing audio I ran the script mentioned here and that fixed the audio. The instructions from that link are:
git clone https://github.com/WeirdTreeThing/chromebook-linux-audio
cd chromebook-linux-audio
./setup-audio

Fixing keyboard I asked my friend Alper for help on fixing the keyboard as he has some experience with Chromebooks. Thanks a lot Alper for the help. I am documenting our steps here for helping others who are facing this issue. Note: This works in X11. For wayland, the steps might differ. To set system-wide keyboard configuration on Debian systems:
$ sudo dpkg-reconfigure keyboard-configuration
Choose Chromebook as the Keyboard Model . Each DE should default to the system configuration, but might need its own configuration which would similarly be available in their GUI tools. But you can check and set it manually from the command line, for example as in this thread. To check the keyboard model Xorg-based DEs:
$ setxkbmap -print -query   grep model:
model:  pc104
To change it temporarily, until a reboot:
$ setxkbmap -model chromebook
If it s not there in KDE settings that would be a bug, To change it persistently for KDE:
$ cat >>.config/kxkbrc <<EOF
[Layout]
Model=chromebook
EOF
This thread was helpful.

10 September 2023

Freexian Collaborators: Debian Contributions: /usr-merge updates, Salsa CI progress, DebConf23 lead-up, and more! (by Utkarsh Gupta)

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.

/usr-merge work, by Helmut Grohne, et al. Given that we now have consensus on moving forward by moving aliased files from / to /usr, we will also run into the problems that the file move moratorium was meant to prevent. The way forward is detecting them early and applying workarounds on a per-package basis. Said detection is now automated using the Debian Usr Merge Analysis Tool. As problems are reported to the bug tracking system, they are connected to the reports if properly usertagged. Bugs and patches for problem categories DEP17-P2 and DEP17-P6 have been filed. After consensus has been reached on the bootstrapping matters, debootstrap has been changed to swap the initial unpack and merging to avoid unpack errors due to pre-existing links. This is a precondition for having base-files install the aliasing symbolic links eventually. It was identified that the root filesystem used by the Debian installer is still unmerged and a change has been proposed. debhelper was changed to recognize systemd units installed to /usr. A discussion with the CTTE and release team on repealing the moratorium has been initiated.

Salsa CI work, by Santiago Ruano Rinc n August was a busy month in the Salsa CI world. Santiago reviewed and merged a bunch of MRs that have improved the project in different aspects: The aptly job got two MRs from Philip Hands. With the first one, the aptly now can export a couple of variables in a dotenv file, and with the second, it can include packages from multiple artifact directories. These MRs bring the base to improve how to test reverse dependencies with Salsa CI. Santiago is working on documenting this. As a result of the mass bug filing done in August, Salsa CI now includes a job to test how a package builds twice in a row. Thanks to the MRs of Sebastiaan Couwenberg and Johannes Schauer Marin Rodrigues. Last but not least, Santiago helped Johannes Schauer Marin Rodrigues to complete the support for arm64-only pipelines.

DebConf23 lead-up, by Stefano Rivera Stefano wears a few hats in the DebConf organization and in the lead up to the conference in mid-September, they ve all been quite busy. As one of the treasurers of DebConf 23, there has been a final budget update, and quite a few payments to coordinate from Debian s Trusted Organizations. We try to close the books from the previous conference at the next one, so a push was made to get DebConf 22 account statements out of TOs and record them in the conference ledger. As a website developer, we had a number of registration-related tasks, emailing attendees and trying to estimate numbers for food and accommodation. As a conference committee member, the job was mostly taking calls and helping the local team to make decisions on urgent issues. For example, getting conference visas issued to attendees required getting political approval from the Indian government. We only discovered the full process for this too late to clear some complex cases, so this required some hard calls on skipping some countries from the application list, allowing everyone else to get visas in time. Unfortunate, but necessary.

Miscellaneous contributions
  • Rapha l Hertzog updated gnome-shell-extension-hamster to a new upstream git snapshot that is compatible with GNOME Shell 44 that was recently uploaded to Debian unstable/testing. This extension makes it easy to start/stop tracking time with Hamster Time Tracker. Very handy for consultants like us who are billing their work per hour.
  • Rapha l also updated zim to the latest upstream release (0.74.2). This is a desktop wiki that can be very useful as a note-taking tool to build your own personal knowledge base or even to manage your personal todo lists.
  • Utkarsh reviewed and sponsored some uploads from mentors.debian.net.
  • Utkarsh helped the local team and the bursary team with some more DebConf activities and helped finalize the data.
  • Thorsten tried to update package hplip. Unfortunately upstream added some new compressed files that need to appear uncompressed in the package. Even though this sounded like an easy task, which seemed to be already implemented in the current debian/rules, the new type of files broke this implementation and made the package no longer buildable. The problem has been solved and the upload will happen soon.
  • Helmut sent 7 patches for cross build failures. Since dpkg-buildflags now defaults to issue arm64-specific compiler flags, more care is needed to distinguish between build architecture flags and host architecture flags than previously.
  • Stefano pushed the final bit of the tox 4 transition over the line in Debian, allowing dh-python and tox 4 to migrate to testing. We got caught up in a few unusual bugs in tox and the way we run it in Debian package building (which had to change with tox 4). This resulted in a couple of patches upstream.
  • Stefano visited Haifa, Israel, to see the proposed DebConf 24 venue and meet with the local team. While the venue isn t committed yet, we have high hopes for it.

14 August 2023

Jonathan McDowell: listadmin3: An imperfect replacement for listadmin on Mailman 3

One of the annoyances I had when I upgraded from Buster to Bullseye (yes, I m talking about an upgrade I did at the end of 2021) is that I ended up moving from Mailman 2 to Mailman 3. Which is fine, I guess, but it meant I could no longer use listadmin to deal with messages held for moderation. At the time I looked around, couldn t find anything, shrugged, and became incredibly bad at performing my list moderation duties. Last week I finally accepted what I should have done at least a year ago and wrote some hopefully not too bad Python to web scrape the Mailman 3 admin interface. It then presents a list of subscribers and held messages that might need approved or discarded. It s heavily inspired by listadmin, but not a faithful copy (partly because it s been so long since I used it that I m no longer familiar with its interface). Despite that I ve called it listadmin3. It currently meets the bar of extremely useful to me so I ve tagged v0.1. You can get it on Github. I d be interested in knowing if it actually works for / is useful to anyone else (I suspect it won t be happy with interfaces configured to not be in English, but that should be solvable). Comment here or reply to my Fediverse announcement. Example usage, cribbed directly from the README:
$ listadmin3
fetching data for partypeople@example.org ... 200 messages
(1/200) 5303: omgitsspam@example.org / March 31, 2023, 6:39 a.m.:
  The message is not from a list member: TOP PICK
(a)ccept, (d)iscard, (b)ody, (h)eaders, (s)kip, (q)uit? q
Moving on...
fetching data for admins@example.org ... 1 subscription requests
(1/1) "The New Admin" <newadmin@example.org>
(a)ccept, (d)iscard, (r)eject, (s)kip, (q)uit? a
1 messages
(1/1) 6560: anastyspamer@example.org / Aug. 13, 2023, 3:15 p.m.:
  The message is not from a list member: Buy my stuff!
(a)ccept, (d)iscard, (b)ody, (h)eaders, (s)kip, (q)uit? d
0 to accept, 1 to discard, proceed? (y/n) y
fetching data for announce@example.org ... nothing in queue
$
There s Debian packaging in the repository (dpkg-buildpackage -uc -us -b will spit you out a .deb) but I m holding off on filing an ITP + actually uploading until I know if it s useful enough for others before doing so. You only really need the listadmin3 file and to ensure you have Python3 + MechanicalSoup installed. (Yes, I still run mailing lists. Hell, I still run a Usenet server.)

9 August 2023

Antoine Beaupr : OpenPGP key transition

This is a short announcement to say that I have changed my main OpenPGP key. A signed statement is available with the cryptographic details but, in short, the reason is that I stopped using my old YubiKey NEO that I have worn on my keyring since 2015. I now have a YubiKey 5 which supports ED25519 which features much shorter keys and faster decryption. It allowed me to move all my secret subkeys on the key (including encryption keys) while retaining reasonable performance. I have written extensive documentation on how to do that OpenPGP key rotation and also YubiKey OpenPGP operations.

Warning on storing encryption keys on a YubiKey People wishing to move their private encryption keys to such a security token should be very careful as there are special precautions to take for disaster recovery. I am toying with the idea of writing an article specifically about disaster recovery for secrets and backups, dealing specifically with cases of death or disabilities.

Autocrypt changes One nice change is the impact on Autocrypt headers, which are considerably shorter. Before, the header didn't even fit on a single line in an email, it overflowed to five lines:
Autocrypt: addr=anarcat@torproject.org; prefer-encrypt=nopreference;
 keydata=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
After the change, the entire key fits on a single line, neat!
Autocrypt: addr=anarcat@torproject.org; prefer-encrypt=nopreference;
 keydata=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
Note that I have implemented my own kind of ridiculous Autocrypt support for the Notmuch Emacs email client I use, see this elisp code. To import keys, I pipe the message into this script which is basically just:
sq autocrypt decode   gpg --import
... thanks to Sequoia best-of-class Autocrypt support.

Note on OpenPGP usage While some have claimed OpenPGP's death, I believe those are overstated. Maybe it's just me, but I still use OpenPGP for my password management, to authenticate users and messages, and it's the interface to my YubiKey for authenticating with SSH servers. I understand people feel that OpenPGP is possibly insecure, counter-intuitive and full of problems, but I think most of those problems should instead be attributed to its current flagship implementation, GnuPG. I have tried to work with GnuPG for years, and it keeps surprising me with evilness and oddities. I have high hopes that the Sequoia project can bring some sanity into this space, and I also hope that RFC4880bis can eventually get somewhere so we have a more solid specification with more robust crypto. It's kind of a shame that this has dragged on for so long, but Update: there's a separate draft called openpgp-crypto-refresh that might actually be adopted as the "OpenPGP RFC" soon! And it doesn't keep real work from happening in Sequoia and other implementations. Thunderbird rewrote their OpenPGP implementation with RNP (which was, granted, a bumpy road because it lost compatibility with GnuPG) and Sequoia now has a certificate store with trust management (but still no secret storage), preliminary OpenPGP card support and even a basic GnuPG compatibility layer. I'm also curious to try out the OpenPGP CA capabilities. So maybe it's just because I'm becoming an old fart that doesn't want to change tools, but so far I haven't seen a good incentive in switching away from OpenPGP, and haven't found a good set of tools that completely replace it. Maybe OpenSSH's keys and CA can eventually replace it, but I suspect they will end up rebuilding most of OpenPGP anyway, just more slowly. If they do, let's hope they avoid the mistakes our community has done in the past at least...

4 August 2023

Reproducible Builds: Reproducible Builds in July 2023

Welcome to the July 2023 report from the Reproducible Builds project. In our reports, we try to outline the most important things that we have been up to over the past month. As ever, if you are interested in contributing to the project, please visit the Contribute page on our website.
Marcel Fourn et al. presented at the IEEE Symposium on Security and Privacy in San Francisco, CA on The Importance and Challenges of Reproducible Builds for Software Supply Chain Security. As summarised in last month s report, the abstract of their paper begins:
The 2020 Solarwinds attack was a tipping point that caused a heightened awareness about the security of the software supply chain and in particular the large amount of trust placed in build systems. Reproducible Builds (R-Bs) provide a strong foundation to build defenses for arbitrary attacks against build systems by ensuring that given the same source code, build environment, and build instructions, bitwise-identical artifacts are created. (PDF)

Chris Lamb published an interview with Simon Butler, associate senior lecturer in the School of Informatics at the University of Sk vde, on the business adoption of Reproducible Builds. (This is actually the seventh instalment in a series featuring the projects, companies and individuals who support our project. We started this series by featuring the Civil Infrastructure Platform project, and followed this up with a post about the Ford Foundation as well as recent ones about ARDC, the Google Open Source Security Team (GOSST), Bootstrappable Builds, the F-Droid project and David A. Wheeler.) Vagrant Cascadian presented Breaking the Chains of Trusting Trust at FOSSY 2023.
Rahul Bajaj has been working with Roland Clobus on merging an overview of environment variations to our website:
I have identified 16 root causes for unreproducible builds in my empirical study, which I have linked to the corresponding documentation. The initial MR right now contains information about 10 root causes. For each root cause, I have provided a definition, a notable instance, and a workaround. However, I have only found workarounds for 5 out of the 10 root causes listed in this merge request. In the upcoming commits, I plan to add an additional 6 root causes. I kindly request you review the text for any necessary refinements, modifications, or corrections. Additionally, I would appreciate the help with documentation for the solutions/workarounds for the remaining root causes: Archive Metadata, Build ID, File System Ordering, File Permissions, and Snippet Encoding. Your input on the identified root causes for unreproducible builds would be greatly appreciated. [ ]

Just a reminder that our upcoming Reproducible Builds Summit is set to take place from October 31st November 2nd 2023 in Hamburg, Germany. Our summits are a unique gathering that brings together attendees from diverse projects, united by a shared vision of advancing the Reproducible Builds effort. During this enriching event, participants will have the opportunity to engage in discussions, establish connections and exchange ideas to drive progress in this vital field. If you re interested in joining us this year, please make sure to read the event page which has more details about the event and location.
There was more progress towards making the Go programming language ecosystem reproducible this month, including: In addition, kpcyrd posted to our mailing list to report that:
while packaging govulncheck for Arch Linux I noticed a checksum mismatch for a tar file I downloaded from go.googlesource.com. I used diffoscope to compare the .tar file I downloaded with the .tar file the build server downloaded, and noticed the timestamps are different.

In Debian, 20 reviews of Debian packages were added, 25 were updated and 25 were removed this month adding to our knowledge about identified issues. A number of issue types were updated, including marking ffile_prefix_map_passed_to_clang being fixed since Debian bullseye [ ] and adding a Debian bug tracker reference for the nondeterminism_added_by_pyqt5_pyrcc5 issue [ ]. In addition, Roland Clobus posted another detailed update of the status of reproducible Debian ISO images on our mailing list. In particular, Roland helpfully summarised that live images are looking good, and the number of (passing) automated tests is growing .
Bernhard M. Wiedemann published another monthly report about reproducibility within openSUSE.
F-Droid added 20 new reproducible apps in July, making 165 apps in total that are published with Reproducible Builds and using the upstream developer s signature. [ ]
The Sphinx documentation tool recently accepted a change to improve deterministic reproducibility of documentation. It s internal util.inspect.object_description attempts to sort collections, but this can fail. The change handles the failure case by using string-based object descriptions as a fallback deterministic sort ordering, as well as adding recursive object-description calls for list and tuple datatypes. As a result, documentation generated by Sphinx will be more likely to be automatically reproducible. Lastly in news, kpcyrd posted to our mailing list announcing a new repro-env tool:
My initial interest in reproducible builds was how do I distribute pre-compiled binaries on GitHub without people raising security concerns about them . I ve cycled back to this original problem about 5 years later and built a tool that is meant to address this. [ ]

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:
In diffoscope development this month, versions 244, 245 and 246 were uploaded to Debian unstable by Chris Lamb, who also made the following changes:
  • Don t include the file size in image metadata. It is, at best, distracting, and it is already in the directory metadata. [ ]
  • Add compatibility with libarchive-5. [ ]
  • Mark that the test_dex::test_javap_14_differences test requires the procyon tool. [ ]
  • Initial work on DOS/MBR extraction. [ ]
  • Move to using assert_diff in the .ico and .jpeg tests. [ ]
  • Temporarily mark some Android-related as XFAIL due to Debian bugs #1040941 & #1040916. [ ]
  • Fix the test skipped reason generation in the case of a version outside of the required range. [ ]
  • Update copyright years. [ ][ ]
  • Fix try.diffoscope.org. [ ]
In addition, Gianfranco Costamagna added support for LLVM version 16. [ ]

Testing framework The Reproducible Builds project operates a comprehensive testing framework (available at tests.reproducible-builds.org) in order to check packages and other artifacts for reproducibility. In July, a number of changes were made by Holger Levsen:
  • General changes:
    • Upgrade Jenkins host to Debian bookworm now that Debian 12.1 is out. [ ][ ][ ][ ]
    • djm: improve UX when rebooting a node fails. [ ]
    • djm: reduce wait time between rebooting nodes. [ ]
  • Debian-related changes:
    • Various refactoring of the Debian scheduler. [ ][ ][ ]
    • Make Debian live builds more robust with respect to salsa.debian.org returning HTTP 502 errors. [ ][ ]
    • Use the legacy SCP protocol instead of the SFTP protocol when transfering Debian live builds. [ ][ ]
    • Speed up a number of database queries thanks, Myon! [ ][ ][ ][ ][ ]
    • Split create_meta_pkg_sets job into two (for Debian unstable and Debian testing) to half the job runtime to approximately 90 minutes. [ ][ ]
    • Split scheduler job into four separate jobs, one for each tested architecture. [ ][ ]
    • Treat more PostgreSQL errors as serious (for some jobs). [ ]
    • Re-enable automatic database documentation now that postgresql_autodoc is back in Debian bookworm. [ ]
    • Remove various hardcoding of Debian release names. [ ]
    • Drop some i386 special casing. [ ]
  • Other distributions:
    • Speed up Alpine SQL queries. [ ]
    • Adjust CSS layout for Arch Linux pages to match 3 and not 4 repos being tested. [ ]
    • Drop the community Arch Linux repo as it has now been merged into the extra repo. [ ]
    • Speed up a number of Arch-related database queries. [ ]
    • Try harder to properly cleanup after building OpenWrt packages. [ ]
    • Drop all kfreebsd-related tests now that it s officially dead. [ ]
  • System health:
    • Always ignore some well-known harmless orphan processes. [ ][ ][ ]
    • Detect another case of job failure due to Jenkins shutdown. [ ]
    • Show all non co-installable package sets on the status page. [ ]
    • Warn that some specific reboot nodes are currently false-positives. [ ]
  • Node health checks:
    • Run system and node health checks for Jenkins less frequently. [ ]
    • Try to restart any failed dpkg-db-backup [ ] and munin-node services [ ].
In addition, Vagrant Cascadian updated the paths in our automated to tests to use the same paths used by the official Debian build servers. [ ]

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:

26 July 2023

Enrico Zini: Mysterious DNS issues

Uhm, salsa is not resolving:
$ git fetch
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
fatal: Could not read from remote repository.
$ ping salsa.debian.org
ping: salsa.debian.org: Name or service not known
But... it is?
$ host salsa.debian.org
salsa.debian.org has address 209.87.16.44
salsa.debian.org has IPv6 address 2607:f8f0:614:1::1274:44
salsa.debian.org mail is handled by 10 mailly.debian.org.
salsa.debian.org mail is handled by 10 mitropoulos.debian.org.
salsa.debian.org mail is handled by 10 muffat.debian.org.
It really is resolving correctly at each step:
$ cat /etc/resolv.conf
# This is /run/systemd/resolve/stub-resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
# [...]
# Run "resolvectl status" to see details about the uplink DNS servers
# currently in use.
# [...]
nameserver 127.0.0.53
options edns0 trust-ad
search fritz.box
$ host salsa.debian.org 127.0.0.53
Using domain server:
Name: 127.0.0.53
Address: 127.0.0.53#53
Aliases:
salsa.debian.org has address 209.87.16.44
salsa.debian.org has IPv6 address 2607:f8f0:614:1::1274:44
salsa.debian.org mail is handled by 10 mailly.debian.org.
salsa.debian.org mail is handled by 10 muffat.debian.org.
salsa.debian.org mail is handled by 10 mitropoulos.debian.org.
# resolvectl status
Global
       Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub
Link 3 (wlp108s0)
    Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.178.1
       DNS Servers: 192.168.178.1 fd00::3e37:12ff:fe99:2301 2a01:b600:6fed:1:3e37:12ff:fe99:2301
        DNS Domain: fritz.box
Link 4 (virbr0)
Current Scopes: none
     Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 9 (enxace2d39ce693)
    Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
         Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.178.1
       DNS Servers: 192.168.178.1 fd00::3e37:12ff:fe99:2301 2a01:b600:6fed:1:3e37:12ff:fe99:2301
        DNS Domain: fritz.box
$ host salsa.debian.org 192.168.178.1
Using domain server:
Name: 192.168.178.1
Address: 192.168.178.1#53
Aliases:
salsa.debian.org has address 209.87.16.44
salsa.debian.org has IPv6 address 2607:f8f0:614:1::1274:44
salsa.debian.org mail is handled by 10 muffat.debian.org.
salsa.debian.org mail is handled by 10 mitropoulos.debian.org.
salsa.debian.org mail is handled by 10 mailly.debian.org.
$ host salsa.debian.org fd00::3e37:12ff:fe99:2301 2a01:b600:6fed:1:3e37:12ff:fe99:2301
Using domain server:
Name: fd00::3e37:12ff:fe99:2301
Address: fd00::3e37:12ff:fe99:2301#53
Aliases:
salsa.debian.org has address 209.87.16.44
salsa.debian.org has IPv6 address 2607:f8f0:614:1::1274:44
salsa.debian.org mail is handled by 10 muffat.debian.org.
salsa.debian.org mail is handled by 10 mitropoulos.debian.org.
salsa.debian.org mail is handled by 10 mailly.debian.org.
Could it be caching?
# systemctl restart systemd-resolved
$ dpkg -s nscd
dpkg-query: package 'nscd' is not installed and no information is available
$ git fetch
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
fatal: Could not read from remote repository.
Could it be something in ssh's config?
$ grep salsa ~/.ssh/config
$ ssh git@salsa.debian.org
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
Something weird with ssh's control sockets?
$ strace -fo /tmp/zz ssh git@salsa.debian.org
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
enrico@ploma:~/lavori/legal/legal$ grep salsa /tmp/zz
393990 execve("/usr/bin/ssh", ["ssh", "git@salsa.debian.org"], 0x7ffffcfe42d8 /* 54 vars */) = 0
393990 connect(3,  sa_family=AF_UNIX, sun_path="/home/enrico/.ssh/sock/git@salsa.debian.org:22" , 110) = -1 ENOENT (No such file or directory)
$ strace -fo /tmp/zz1 ssh -S none git@salsa.debian.org
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
$ grep salsa /tmp/zz1
394069 execve("/usr/bin/ssh", ["ssh", "-S", "none", "git@salsa.debian.org"], 0x7ffd36cbfde8 /* 54 vars */) = 0
How is ssh trying to resolve salsa.debian.org?
393990 socket(AF_UNIX, SOCK_STREAM SOCK_CLOEXEC SOCK_NONBLOCK, 0) = 3
393990 connect(3,  sa_family=AF_UNIX, sun_path="/run/systemd/resolve/io.systemd.Resolve" , 42) = 0
393990 sendto(3, " \"method\":\"io.systemd.Resolve.Re"..., 99, MSG_DONTWAIT MSG_NOSIGNAL, NULL, 0) = 99
393990 mmap(NULL, 135168, PROT_READ PROT_WRITE, MAP_PRIVATE MAP_ANONYMOUS, -1, 0) = 0x7f4fc71ca000
393990 recvfrom(3, 0x7f4fc71ca010, 135152, MSG_DONTWAIT, NULL, NULL) = -1 EAGAIN (Resource temporarily unavailable)
393990 ppoll([ fd=3, events=POLLIN ], 1,  tv_sec=119, tv_nsec=999917000 , NULL, 8) = 1 ([ fd=3, revents=POLLIN ], left  tv_sec=119, tv_nsec=998915689 )
393990 recvfrom(3, " \"error\":\"io.systemd.System\",\"pa"..., 135152, MSG_DONTWAIT, NULL, NULL) = 56
393990 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
393990 close(3)                         = 0
393990 munmap(0x7f4fc71ca000, 135168)   = 0
393990 getpid()                         = 393990
393990 write(2, "ssh: Could not resolve hostname "..., 77) = 77
Something weird with resolved?
$ resolvectl query salsa.debian.org
salsa.debian.org: resolve call failed: Lookup failed due to system error: Invalid argument
Let's try disrupting what ssh is trying and failing:
# mv /run/systemd/resolve/io.systemd.Resolve /run/systemd/resolve/io.systemd.Resolve.backup
$ strace -o /tmp/zz2 ssh -S none -vv git@salsa.debian.org
OpenSSH_9.2p1 Debian-2, OpenSSL 3.0.9 30 May 2023
debug1: Reading configuration data /home/enrico/.ssh/config
debug1: /home/enrico/.ssh/config line 1: Applying options for *
debug1: /home/enrico/.ssh/config line 228: Applying options for *.debian.org
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: include /etc/ssh/ssh_config.d/*.conf matched no files
debug1: /etc/ssh/ssh_config line 21: Applying options for *
debug2: resolving "salsa.debian.org" port 22
ssh: Could not resolve hostname salsa.debian.org: Name or service not known
$ tail /tmp/zz2
394748 prctl(PR_CAPBSET_READ, 0x29 /* CAP_??? */) = -1 EINVAL (Invalid argument)
394748 munmap(0x7f27af5ef000, 164622)   = 0
394748 rt_sigprocmask(SIG_BLOCK, [HUP USR1 USR2 PIPE ALRM CHLD TSTP URG VTALRM PROF WINCH IO], [], 8) = 0
394748 futex(0x7f27ae5feaec, FUTEX_WAKE_PRIVATE, 2147483647) = 0
394748 openat(AT_FDCWD, "/run/systemd/machines/salsa.debian.org", O_RDONLY O_CLOEXEC) = -1 ENOENT (No such file or directory)
394748 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
394748 getpid()                         = 394748
394748 write(2, "ssh: Could not resolve hostname "..., 77) = 77
394748 exit_group(255)                  = ?
394748 +++ exited with 255 +++
$ machinectl list
No machines.
# resolvectl flush-caches
$ resolvectl query salsa.debian.org
salsa.debian.org: resolve call failed: Lookup failed due to system error: Invalid argument
# resolvectl reset-statistics
$ resolvectl query salsa.debian.org
salsa.debian.org: resolve call failed: Lookup failed due to system error: Invalid argument
# resolvectl reset-server-features
$ resolvectl query salsa.debian.org
salsa.debian.org: resolve call failed: Lookup failed due to system error: Invalid argument
# resolvectl monitor
  Q: salsa.debian.org IN A
  Q: salsa.debian.org IN AAAA
  S: EINVAL
  A: debian.org IN NS sec2.rcode0.net
  A: debian.org IN NS sec1.rcode0.net
  A: debian.org IN NS nsp.dnsnode.net
  A: salsa.debian.org IN A 209.87.16.44
  A: debian.org IN NS dns4.easydns.info
I guess I won't be using salsa today, and I wish I understood why. Update: as soon as I pushed this post to my blog (via ssh) salsa started resolving again.

13 July 2023

Emmanuel Kasper: Debian 11 to Debian 12 (Bookworm) Upgrade Report

Laptop + Workstation My workstation was initially installed with Debian 8 back in the day, so I might have carried a lot of configuration cruft.
Indeed. I followed the recommended upgrades documentation (apt upgrade --without-new-pkgs followed by apt full-upgrade). And when executing apt full-upgrade I had the following error:
Preparing to unpack .../71-python3-numpy_1%3a1.24.2-1_amd64.deb ...
Unpacking python3-numpy (1:1.24.2-1) over (1:1.19.5-1) ...
dpkg: error processing archive /tmp/apt-dpkg-install-ibI85v/71-python3-numpy_1%3a1.24.2-1_amd64.deb (--unpack):
 trying to overwrite '/usr/bin/f2py', which is also in package python-numpy 1:1.16.5-5
Deleting the python-numpy package and resuming the upgrade with apt --fix-broken install followed by apt full-upgrade allowed the upgrade to complete successfully. This was already metioned in a Debian bug report and would have been avoided if I had purged the locally obsolete packages after upgrading to Debian 11. On laptop and workstation, after the upgrade, for unclear reasons, the gnome3 user extensions were disabled. I reenabled the extensions manually with
gsettings set org.gnome.shell disable-user-extensions false
Finally podman, had a major upgrade from 3 to 4, and a backward-incompatible configuration change. If a custom configuration file was in place in /etc/containers/storage.conf to override the default storage options, you need now to add the following stanza
[storage]
runroot="/run/containers/storage"
graphRoot="/var/lib/containers/storage"
in that file.
Otherwise you ll get the error Failed to obtain podman configuration: runroot must be set when running any podman command. This was discussed upstream. Cloud server (VM) Everything worked flawlessly, nothing to report. Conclusion Again a great Debian release, very happy that I could update three systems with ten thousands of packages with so little fuss. For my small home server running RHEL 8 (with the no cost sub) I will do a reinstall on newer hardware.

12 July 2023

Freexian Collaborators: Debian Contributions: /usr-merge updates, DebConf Bursary prep, and more! (by Utkarsh Gupta)

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.

/usr-merge, by Helmut Grohne, et al The work on /usr-merge continues from May. The lengthy discussion was condensed into a still lengthy rewrite of DEP17 listing all known problems and proposed mitigations. An initial consensus call did not resolve all questions, but we now have rough consensus on finalizing the transition without relying on major changes to dpkg. Other questions still have diverging opinions and some matters such as how to not break backports are still missing satisfying answers.

DebConf Bursary prep, by Utkarsh Gupta DebCamp and DebConf is happening from 03rd September to 17th September in Kochi, India, and the DebConf Bursary team is gearing up for that. After extending the bursary deadline (catering to the requests coming in from various people), we ve finally managed to clock over 260 bursary requests. The team is set up and we re starting to review the applications. The team intends to roll out the result as soon as possible.

debci, by Helmut Grohne As Freexian is working on deploying autopkgtests for the LTS and ELTS services, debci and autopkgtests were improved in Debian to better deal with derivatives (e.g. by better supporting external package signing keyrings). Other aspects that are not deployed on ci.debian.net such as the qemu backend were also improved. We express thanks to the relevant maintainers Antonio Terceiro, Paul Gevers and Simon McVittie for their timely reviews and merges of our changes.

Miscellaneous contributions
  • Following the release of Debian 12, Rapha l Hertzog updated tracker.debian.org to be aware of trixie. He also pushed some fixes to distro-tracker (the software powering tracker.debian.org) and released version 1.2.0 (since the former release was lacking fixes to run on Debian 12 bookworm).
  • Following the release of Debian 12, Helmut Grohne updated crossqa.debian.net systems. He also sent 7 patches for cross build failures and continued adapting rebootstrap to changes in unstable.
  • Santiago Ruano Rinc n started to work on how to improve the robustness of Salsa CI s pipeline for some jobs failing frequently.
  • Thorsten Alteholz did security updates of cpdb-libs in Unstable and Bookworm.
  • Stefano Rivera upgraded pixelfed.debian.social to bookworm.
  • Stefano started an re2 library transition, and started preparation for the next transition.
  • Helmut Grohne updated debvm in unstable releasing changes that accumulated during the freeze.
  • Stefano did some work on the website and infrastructure for DebConf 23.
  • Utkarsh Gupta helped review and fix open redmine bugs and fix them all in unstable.

10 July 2023

Michael Ablassmeier: Java timezone sheanigans

While running CI tests for a application that is implemented in C and Java, some configuration scripts set the current timezone. The C implemented parts catch the change just nicely, but the java related parts still report the default image timezone. A simple example:
import java.util.*;
import java.text.*;
class simpleTest
 
        public static void main(String args[])
         
           Calendar cal = Calendar.getInstance();
           System.out.println("TIME ZONE :"+ cal.getTimeZone().getDisplayName());
         
 
Result:
vagrant@vm:~$ sudo timedatectl set-timezone America/Aruba 
vagrant@vm:~$ timedatectl 
[..]
                Time zone: America/Aruba (AST, -0400)
[..]
vagrant@vm:~$ java test.java
TIME ZONE :Central European Standard Time
vagrant@vm:~$ ls -alh /etc/localtime 
lrwxrwxrwx 1 root root 35 Jul 10 14:41 /etc/localtime -> ../usr/share/zoneinfo/America/Aruba
It appears the Java implementation uses /etc/timezone as source, not /etc/localtime.
vagrant@vm:~$ echo America/Aruba   sudo tee /etc/timezone 
America/Aruba
vagrant@vm:~$ java test.java
TIME ZONE :Atlantic Standard Time
dpkg-reconfigure tzdata updates this file as well, so using timedatectl only won t be enough (at least not on Debian based systems which run java based applications.)

8 July 2023

Russell Coker: Sandboxing Phone Apps

As a follow up to Wayland [1]: A difficult problem with Linux desktop systems (which includes phones and tablets) is restricting application access so that applications can t mess with each other s data or configuration but also allowing them to share data as needed. This has been mostly solved for Android but that involved giving up all legacy Linux apps. I think that we need to get phones capable of running a full desktop environment and having Android level security on phone apps and regular desktop apps. My interest in this is phones running Debian and derivatives such as PureOS. But everything I describe in this post should work equally well for all full featured Linux distributions for phones such as Arch, Gentoo, etc and phone based derivatives of those such as Manjaro. It may be slightly less applicable to distributions such as Alpine Linux and it s phone derivative PostmarketOS, I would appreciate comments from contributors to PostmarketOS or Alpine Linux about this. I ve investigated some of the ways of solving these problems. Many of the ways of doing this involves namespaces. The LWN articles about namespaces are a good background to some of these technologies [2]. The LCA keynote lecture Containers aka crazy user space fun by Jess Frazelle has a good summary of some of the technology [3]. One part that I found particularly interesting was the bit about recognising the container access needed at compile time. This can also be part of recognising bad application design at compile time, it s quite common for security systems to flag bad security design in programs. Firejail To sandbox applications you need to have some method of restricting what they do, this means some combination of namespaces and similar features. Here s an article on sandboxing with firejail [4]. Firejail uses namespaces, seccomp-bpf, and capabilities to restrict programs. It allows bind mounts if run as root and if not run as root it can restrict file access by name and access to networking, system calls, and other features. It has a convenient learning mode that generates policy for you, so if you have a certain restricted set of tasks that an application is to perform you can run it once and then force it to do only the same operations in future. I recommend that everyone who is still reading at this point try out firejail. Here s an example of what you can do:
# create a profile
firejail --build=xterm.profile xterm
# now this run can only do what the previous run did
firejail --profile=xterm.profile xterm
Note that firejail is SETUID root so can potentially reduce system security and it has had security issues in the past. In spite of that it can be good for allowing a trusted user to run programs with less access to the system. Also it is a good way to start learning about such things. I don t think it s a good solution for what I want to do. But I won t rule out the possibility of using it at some future time for special situations. Bubblewrap I tried out firejail with the browser Epiphany (Debian package epiphany-browser) on my Librem5, but that didn t work as Epiphany uses /usr/bin/bwrap (bubblewrap) for it s internal sandboxing (here is an informative blog post about the history of bubblewrap AKA xdg-app-helper which was developed as part of flatpak [5]). The Epiphany bubblewrap sandbox is similar to the situation with Chrome/Chromium which have internal sandboxing that s incompatible with firejail. The firejail man page notes that it s not compatible with Snap, Flatpack, and similar technologies. One issue this raises is that we can t have a namespace based sandboxing system applied to all desktop apps with no extra configuration as some desktop apps won t work with it. Bubblewrap requires setting kernel.unprivileged_userns_clone=1 to run as non-root (IE provide the normal and expected functionality) which potentially reduces system security. Here is an example of a past kernel bug that was exploitable by creating a user namespace with CAP_SYS_ADMIN [6]. But it s the default in recent Debian kernels which means that the issues have been reviewed and determined to be a reasonable trade-off and also means that many programs will use the feature and break if it s disabled. Here is an example of how to use Bubblewrap on Debian, after installing the bubblewrap run the following command. Note that the new-session option (to prevent injecting characters in the keyboard buffer with TIOCSTI) makes the session mostly unusable for a shell.
bwrap --ro-bind /usr /usr --symlink usr/lib64 /lib64 --symlink usr/lib /lib --proc /proc --dev /dev --unshare-pid --die-with-parent bash
Here is an example of using Bubblewrap to sandbox the game Warzone2100 running with Wayland/Vulkan graphics and Pulseaudio sound.
bwrap --bind $HOME/.local/share/warzone2100 $HOME/.local/share/warzone2100 --bind /run/user/$UID/pulse /run/user/$UID/pulse --bind /run/user/$UID/wayland-0 /run/user/$UID/wayland-0 --bind /run/user/$UID/wayland-0.lock /run/user/$UID/wayland-0.lock --ro-bind /usr /usr --symlink usr/bin /bin --symlink usr/lib64 /lib64 --symlink usr/lib /lib --proc /proc --dev /dev --unshare-pid --dev-bind /dev/dri /dev/dri --ro-bind $HOME/.pulse $HOME/.pulse --ro-bind $XAUTHORITY $XAUTHORITY --ro-bind /sys /sys --new-session --die-with-parent warzone2100
Here is an example of using Bubblewrap to sandbox the Debian bug reporting tool reportbug
bwrap --bind /tmp /tmp --ro-bind /etc /etc --ro-bind /usr /usr --ro-bind /var/lib/dpkg /var/lib/dpkg --symlink usr/sbin /sbin --symlink usr/bin /bin --symlink usr/lib64 /lib64 --symlink usr/lib /lib --symlink /usr/lib32 /lib32 --symlink /usr/libx32 /libx32 --proc /proc --dev /dev --die-with-parent --unshare-ipc --unshare-pid reportbug
Here is an example shell script to wrap the build process for Debian packages. This needs to run with unshare-user and specifying the UID as 0 because fakeroot doesn t work in the container, I haven t worked out why but doing it through the container is a better method anyway. This script shares read-write the parent of the current directory as the Debian build process creates packages and metadata files in the parent directory. This will prevent the automatic signing scripts which is a feature not a bug, so after building packages you have to sign the .changes file with debsign. One thing I just learned is that the Debian build system Sbuild can use chroots for building packages for similar benefits [7]. Some people believe that sbuild is the correct way of doing it regardless of the chroot issue. I think it s too heavy-weight for most of my Debian package building, but even if I had been convinced I d still share the information about how to use bwrap as Debian is about giving users choice.
#!/bin/bash
set -e
BUILDDIR=$(realpath $(pwd)/..)
exec bwrap --bind /tmp /tmp --bind $BUILDDIR $BUILDDIR --ro-bind /etc /etc --ro-bind /usr /usr --ro-bind /var/lib/dpkg /var/lib/dpkg --symlink usr/bin /bin --symlink usr/lib64 /lib64 --symlink usr/lib /lib --proc /proc --dev /dev --die-with-parent --unshare-user --unshare-ipc --unshare-net --unshare-pid --new-session --uid 0 --gid 0 $@
Here is an informative blog post about using Bubblewrap with Seccomp (BPF) [8]. In a future post I ll write about how to get this sort of thing going but I ll just leave the URL here for people who want to do it on their own. The source for the flatpak-run program is the only example I could find of using Seccomp with Bubblewrap [9]. A lot of that code is worth copying for application sandboxing, maybe the entire program. Unshare The unshare command from the util-linux package has a large portion of the Bubblewrap functionality. The things that it doesn t do like creating a new session can be done by other utilities. Here is an example of creating a container with unshare and then using cgroups with it [10]. systemd --user Recent distributions have systemd support for running a user session, the Arch Linux Wiki has a good description of how this works [11]. The units for a user are .service files stored in /usr/lib/systemd/user/ (distribution provided), ~/.local/share/systemd/user/ (user installed applications in debian a link to ~/.config/systemd/user/), ~/.config/systemd/user/ (for manual user config), and /etc/systemd/user/ (local sysadmin provided) Here are some example commands for manipulating this:
# show units running for the current user
systemctl --user
# show status of one unit
systemctl --user status kmail.service
# add an environment variable to the list for all user units
systemctl --user import-environment XAUTHORITY
# start a user unit
systemctl --user start kmail.service
# analyse security for all units for the current user
systemd-analyze --user security
# analyse security for one unit
systemd-analyze --user security kmail.service
Here is a test kmail.service file I wrote to see what could be done for kmail, I don t think that kmail is the app most needing to be restricted it is in more need of being protected from other apps but it still makes a good test case. This service file took it from the default risk score of 9.8 (UNSAFE) to 6.3 (MEDIUM) even though I was getting the error code=exited, status=218/CAPABILITIES when I tried anything that used capabilities (apparently due to systemd having some issue talking to the kernel).
[Unit]
Description=kmail
[Service]
ExecStart=/usr/bin/kmail
# can not limit capabilities (code=exited, status=218/CAPABILITIES)
#CapabilityBoundingSet=~CAP_SYS_TIME CAP_SYS_PACCT CAP_KILL CAP_WAKE_ALARM CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER CAP_IPC_OWNER CAP_LINUX_IMMUTABLE CAP_IPC_LOCK CAP_SYS_MODULE CAP_SYS_TTY_CONFIG CAP_SYS_BOOT CAP_SYS_CHROOT CAP_BLOCK_SUSPEND CAP_LEASE CAP_MKNOD CAP_CHOWN CAP_FSETID CAP_SETFCAP CAP_SETGID CAP_SETUID CAP_SETPCAP CAP_SYS_RAWIO CAP_SYS_PTRACE CAP_SYS_NICE CAP_SYS_RESOURCE CAP_NET_ADMIN CAP_NET_BIND_SERVICE CAP_NET_BROADCAST CAP_NET_RAW CAP_SYS_ADMIN CAP_SYSLOG
# also 218 for ProtectKernelModules PrivateDevices ProtectKernelLogs ProtectClock
# MemoryDenyWriteExecute stops it displaying message content (bad)
# needs @resources and @mount to startup
# needs @privileged to display message content
SystemCallFilter=~@cpu-emulation @debug @raw-io @reboot @swap @obsolete
SystemCallArchitectures=native
UMask=077
NoNewPrivileges=true
ProtectControlGroups=true
PrivateMounts=false
RestrictNamespaces=~user pid net uts mnt cgroup ipc
RestrictSUIDSGID=true
ProtectHostname=true
LockPersonality=true
ProtectKernelTunables=true
RestrictAddressFamilies=~AF_PACKET
RestrictRealtime=true
ProtectSystem=strict
ProtectProc=invisible
PrivateUsers=true
[Install]
When I tried to use the TemporaryFileSystem=%h directive (to make the home directory a tmpfs the most basic step in restricting what a regular user application can do) I got the error (code=exited, status=226/NAMESPACE) . So I don t think the systemd user setup competes with bubblewrap for restricting user processes. But if anyone else can start where I left off and go further then that will be interesting. Systemd-run The following shell script runs firefox as a dynamic user via systemd-run, running this asks for the root password and any mechanism for allowing that sort of thing opens potential security holes. So at this time while it s an interesting feature I don t think it is suitable for running regular applications on a phone or Linux desktop.
#!/bin/bash
# systemd-run Firefox with DynamicUser and home directory.
#
# Run as a non-root user.
# Or, run as root and change $USER below.
SANDBOX_MINIMAL=(
    --property=DynamicUser=1
    --property=StateDirectory=openstreetmap
    # --property=RootDirectory=/debian_sid
)
SANDBOX_X11=(
    # Sharing Xorg always defeats security, regardless of any sandboxing tech,
    # but the config is almost ready for Wayland, and there's Xephyr.
#    --property=LoadCredential=.ICEauthority:/home/$USER/.ICEauthority
    --property=LoadCredential=.Xauthority:/home/$USER/.Xauthority
    --property=Environment=DISPLAY=:0
)
SANDBOX_FIREFOX=(
    # hardware-accelerated rendering
    --property=BindPaths=/dev/dri
    # webcam
    # --property=SupplementaryGroups=video
)
systemd-run  \
    "$ SANDBOX_MINIMAL[@] "  "$ SANDBOX_X11[@] " "$ SANDBOX_FIREFOX[@] " \
    bash -c '
        export XAUTHORITY="$CREDENTIALS_DIRECTORY"/.Xauthority
        export ICEAUTHORITY="$CREDENTIALS_DIRECTORY"/.ICEauthority
        export HOME="$STATE_DIRECTORY"/home
        firefox --no-remote about:blank
    '
Qubes OS Here is an interesting demo video of QubesOS [12] which shows how it uses multiple VMs to separate different uses. Here is an informative LCA presentation about Qubes which shows how it asks the user about communication between VMs and access to hardware [13]. I recommend that everyone who hasn t seen Qubes in operation watch the first video and everyone who isn t familiar with the computer science behind it watch the second video. Qubes appears to be a free software equivalent to NetTop as far as I can tell without ever being able to use NetTop. I don t think Qubes is a good match for my needs in general use and it definitely isn t a good option for phones (VMs use excessive CPU on phones). But it s methods for controlling access have some ideas that are worth copying. File Access XDG Desktop Portal One core issue for running sandboxed applications is to allow them to access files permitted by the user but no other files. There are two main parts to this problem, the easier one is to have each application have it s own private configuration directory which can be addressed by bind mounts, MAC systems, running each application under a different UID or GID, and many other ways. The hard part of file access is to allow the application to access random files that the user wishes. For example I want my email program, IM program, and web browser to be able to save files and also to be able to send arbitrary files via email, IM, and upload to web sites. But I don t want one of those programs to be able to access all the files from the others if it s compromised. So only giving programs access to arbitrary files when the user chooses such a file makes sense. There is a package xdg-desktop-portal which provides a dbus interface for opening files etc for a sandboxed application [14]. This portal has backends for KDE, GNOME, and Wayland among others which allow the user to choose which file or files the application may access. Chrome/Chromium is one well known program that uses the xdg-desktop-portal and does it s own sandboxing. To use xdg-desktop-portal an application must be modified to use that interface instead of opening files directly, so getting this going with all Internet facing applications will take some work. But the documentation notes that the portal API gives a consistent user interface for operations such as opening files so it can provide benefits even without a sandboxed environment. This technology was developed for Flatpak and is now also used for Snap. It also has a range of APIs for accessing other services [15]. Flatpak Flatpack is a system for distributing containerised versions of applications with some effort made to improve security. Their development of bubblewrap and xdg-desktop-portal is really good work. However the idea of having software packaged with all libraries it needs isn t a good one, here s a blog post covering some of the issues [16]. The web site flatkill.org has been registered to complain about some Flatpak problems [17]. They have some good points about the approach that Flatpak project developers have taken towards some issues. They also make some points about the people who package software not keeping up to date with security fixes and not determining a good security policy for their pak. But this doesn t preclude usefully using parts of the technology for real security benefits. If parts of Flatpak like Bubblewrap and xdg-portal are used with good security policies on programs that are well packaged for a distribution then these issues would be solved. The Flatpak app author s documentation about package requirements [18] has an overview of security features that is quite reasonable. If most paks follow that then it probably isn t too bad. I reviewed the manifests of a few of the recent paks and they seemed to have good settings. In the amount of time I was prepared to spend investigating this I couldn t find evidence to support the Flatkill claim about Flatpaks granting obviously inappropriate permissions. But the fact that the people who run Flathub decided to put a graph of installs over time on the main page for each pak while making the security settings only available by clicking the Manifest github link, clicking on a JSON or YAML file, and then searching for the right section in that shows where their priorities lie. The finish-args section of the Flatpak manifest (the section that describes the access to the system) seems reasonably capable and not difficult for users to specify as well as being in common use. It seems like it will be easy enough to take some code from Flatpak for converting the finish-args into Bubblewrap parameters and then use the manifest files from Flathub as a starting point for writing application security policy for Debian packages. Snap Snap is developed by Canonical and seems like their version of Flatpak with some Docker features for managing versions, the Getting Started document is worth reading [19]. They have Connections between different snaps and the system where a snap registers a plug that connects to a socket which can be exposed by the system (EG the camera socket) or another snap. The local admin can connect and disconnect them. The connections design reminds me of the Android security model with permitting access to various devices. The KDE Neon extension [20] has been written to add Snap support to KDE. Snap seems quite usable if you have an ecosystem of programs using it which Canonical has developed. But it has all the overheads of loopback mounts etc that you don t want on a mobile device and has the security issues of libraries included in snaps not being updated. A quick inspection of an Ubuntu 22.04 system I run (latest stable release) has Firefox 114.0.2-1 installed which includes libgcrypt.so.20.2.5 which is apparently libgcrypt 1.8.5 and there are CVEs relating to libgcrypt versions before 1.9.4 and 1.8.x versions before 1.8.8 which were published in 2021 and updated in 2022. Further investigation showed that libgcrypt came from the gnome-3-38-2004 snap (good that it doesn t require all shared objects to be in the same snap, but that it has old versions in dependencies). The gnome-3-38-2004 snap is the latest version so anyone using the Snap of Firefox seems to have no choice but to have what appears to be insecure libraries. The strict mode means that the Snap in question has no system access other than through interfaces [21]. SE Linux and Apparmor The Librem5 has Apparmor running by default. I looked into writing Apparmor policy to prevent Epiphany from accessing all files under the home directory, but that would be a lot of work. Also at least one person has given up on maintaining an Epiphany profile for Apparmor because it changes often and it s sandbox doesn t work well with Apparmor [22]. This was not a surprise to me at all, SE Linux policy has the same issues as Apparmor in this regard. The Ubuntu Security Team Application Confinement document [23] is worth reading. They have some good plans for using AppArmor as part of solving some of these problems. I plan to use SE Linux for that. Slightly Related Things One thing for the future is some sort of secure boot technology, the LCA lecture Becoming a tyrant: Implementing secure boot in embedded devices [24] has some ideas for the future. The Betrusted project seems really interesting, see Bunnie s lecture about how to create a phone size security device with custom OS [25]. The Betrusted project web page is worth reading too [26]. It would be ironic to have a phone as your main PC that is the same size as your security device, but that seems to be the logical solution to several computing problems. Whonix is a Linux distribution that has one VM for doing Tor stuff and another VM for all other programs which is only allowed to have network access via the Tor VM [27]. Xpra does for X programs what screen/tmux do for text mode programs [28]. It allows isolating X programs from each other in ways that are difficult to impossible with a regular X session. In an ideal situation we could probably get the benefits we need with just using Wayland, but if there are legacy apps that only have X support this could help. Conclusion I think that currently the best option for confining desktop apps is Bubblewrap on Wayland. Maybe with a modified version of Flatpak-run to run it and with app modifications to use the xdg-portal interfaces as much as possible. That should be efficient enough in storage space, storage IO performance, memory use, and CPU use to run on phones while giving some significant benefits. Things to investigate are how much code from Flatpak to use, how to most efficiently do the configuration (maybe the Flatpak way because it s known and seems effective), how to test this (and have regression tests), and what default settings to use. Also BPF is a big thing to investigate.

1 July 2023

Paul Wise: FLOSS Activities June 2023

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

Changes

Issues

Review
  • Spam: reported 29 Debian mailing list posts
  • Debian wiki: RecentChanges for the month
  • Debian BTS usertags: changes for the month
  • Debian screenshots:
    • approved lsd stockfish x86dis
    • rejected libselinux1 (photo), stockfish (mobile app), php-bcmath (selfie), chromium-browser/binutils-alpha-linux-gnu (medical photo), weboob-qt (QR code)

Administration
  • Debian QA services: deploy changes
  • Debian IRC: updated #debian-live admin list
  • Debian mentors: investigate reason for missing package
  • Debian wiki: unblock IP addresses, approve accounts

Communication

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

11 June 2023

Michael Prokop: What to expect from Debian/bookworm #newinbookworm

Bookworm Banner, Copyright 2022 Juliette Taka Debian v12 with codename bookworm was released as new stable release on 10th of June 2023. Similar to what we had with #newinbullseye and previous releases, now it s time for #newinbookworm! I was the driving force at several of my customers to be well prepared for bookworm. As usual with major upgrades, there are some things to be aware of, and hereby I m starting my public notes on bookworm that might be worth also for other folks. My focus is primarily on server systems and looking at things from a sysadmin perspective. Further readings As usual start at the official Debian release notes, make sure to especially go through What s new in Debian 12 + Issues to be aware of for bookworm. Package versions As a starting point, let s look at some selected packages and their versions in bullseye vs. bookworm as of 2023-02-10 (mainly having amd64 in mind):
Package bullseye/v11 bookworm/v12
ansible 2.10.7 2.14.3
apache 2.4.56 2.4.57
apt 2.2.4 2.6.1
bash 5.1 5.2.15
ceph 14.2.21 16.2.11
docker 20.10.5 20.10.24
dovecot 2.3.13 2.3.19
dpkg 1.20.12 1.21.22
emacs 27.1 28.2
gcc 10.2.1 12.2.0
git 2.30.2 2.39.2
golang 1.15 1.19
libc 2.31 2.36
linux kernel 5.10 6.1
llvm 11.0 14.0
lxc 4.0.6 5.0.2
mariadb 10.5 10.11
nginx 1.18.0 1.22.1
nodejs 12.22 18.13
openjdk 11.0.18 + 17.0.6 17.0.6
openssh 8.4p1 9.2p1
openssl 1.1.1n 3.0.8-1
perl 5.32.1 5.36.0
php 7.4+76 8.2+93
podman 3.0.1 4.3.1
postfix 3.5.18 3.7.5
postgres 13 15
puppet 5.5.22 7.23.0
python2 2.7.18 (gone!)
python3 3.9.2 3.11.2
qemu/kvm 5.2 7.2
ruby 2.7+2 3.1
rust 1.48.0 1.63.0
samba 4.13.13 4.17.8
systemd 247.3 252.6
unattended-upgrades 2.8 2.9.1
util-linux 2.36.1 2.38.1
vagrant 2.2.14 2.3.4
vim 8.2.2434 9.0.1378
zsh 5.8 5.9
Linux Kernel The bookworm release ships a Linux kernel based on version 6.1, whereas bullseye shipped kernel 5.10. As usual there are plenty of changes in the kernel area, including better hardware support, and this might warrant a separate blog entry, but to highlight some changes: See Kernelnewbies.org for further changes between kernel versions. Configuration management puppet s upstream sadly still doesn t provide packages for bookworm (see PA-4995), though Debian provides puppet-agent and puppetserver packages, and even puppetdb is back again, see release notes for further information. ansible is also available and made it with version 2.14 into bookworm. Prometheus stack Prometheus server was updated from v2.24.1 to v2.42.0 and all the exporters that got shipped with bullseye are still around (in more recent versions of course). Virtualization docker (v20.10.24), ganeti (v3.0.2-3), libvirt (v9.0.0-4), lxc (v5.0.2-1), podman (v4.3.1), openstack (Zed), qemu/kvm (v7.2), xen (v4.17.1) are all still around. Vagrant is available in version 2.3.4, also Vagrant upstream provides their packages for bookworm already. If you re relying on VirtualBox, be aware that upstream doesn t provide packages for bookworm yet (see ticket 21524), but thankfully version 7.0.8-dfsg-2 is available from Debian/unstable (as of 2023-06-10) (VirtualBox isn t shipped with stable releases since quite some time due to lack of cooperation from upstream on security support for older releases, see #794466). rsync rsync was updated from v3.2.3 to v3.2.7, and we got a few new options: OpenSSH OpenSSH was updated from v8.4p1 to v9.2p1, so if you re interested in all the changes, check out the release notes between those version (8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1 + 9.2). Let s highlight some notable new features: One important change you might wanna be aware of is that as of OpenSSH v8.8, RSA signatures using the SHA-1 hash algorithm got disabled by default, but RSA/SHA-256/512 AKA RSA-SHA2 gets used instead. OpenSSH has supported RFC8332 RSA/SHA-256/512 signatures since release 7.2 and existing ssh-rsa keys will automatically use the stronger algorithm where possible. A good overview is also available at SSH: Signature Algorithm ssh-rsa Error. Now tools/libraries not supporting RSA-SHA2 fail to connect to OpenSSH as present in bookworm. For example python3-paramiko v2.7.2-1 as present in bullseye doesn t support RSA-SHA2. It tries to connect using the deprecated RSA-SHA-1, which is no longer offered by default with OpenSSH as present in bookworm, and then fails. Support for RSA/SHA-256/512 signatures in Paramiko was requested e.g. at #1734, and eventually got added to Paramiko and in the end the change made it into Paramiko versions >=2.9.0. Paramiko in bookworm works fine, and a backport by rebuilding the python3-paramiko package from bookworm for bullseye solves the problem (BTDT). Misc unsorted Thanks to everyone involved in the release, happy upgrading to bookworm, and let s continue with working towards Debian/trixie. :)

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