Hi!

I am trying to set up sbuild-qemu to build (and test) Debian packages.

After creating the virtual machine image:

  $ mkdir -p ~/.cache/sbuild/build
  $ cd /dev/shm
  $ TMPDIR=/dev/shm mmdebstrap-autopkgtest-build-qemu \
                    --size=25G --boot=efi sid unstable-autopkgtest-amd64.img
  $ mv -i unstable-autopkgtest-amd64.img ~/.cache/sbuild/

I prepared the following configuration file:

  $ cat ~/.sbuildrc
  $source_only_changes = 1;
  $autopkgtest_require_success = 1;
  $lintian_require_success = 0;
  $piuparts_require_success = 1;
  $run_autopkgtest = 1;
  $run_lintian = 1;
  $run_piuparts = 1;
  $build_dir = "$HOME/.cache/sbuild/build";

  # don't remove this, Perl needs it:
  1;

I can update the virtual machine (if I create a symlink, see bug [#1061816]):

  $ sbuild-qemu-update --boot=efi unstable-autopkgtest-amd64.img

[#1061816]: <https://bugs.debian.org/1061816#98>

But, when I try to build a package from withing the unpacked source
tree:

  $ sbuild-qemu --boot=efi --overlay-dir=/dev/shm
  sbuild --dist unstable --purge-build=never --purge-deps=never --chroot-mode=autopkgtest --autopkgtest-virt-server=qemu --autopkgtest-virt-server-opt --overlay-dir=/dev/shm --autopkgtest-virt-server-opt --qemu-architecture=x86_64 --autopkgtest-virt-server-opt --ram-size=2048 --autopkgtest-virt-server-opt --cpus=2 --autopkgtest-virt-server-opt --boot=efi --autopkgtest-virt-server-opt /home/$USER/.cache/sbuild/unstable-autopkgtest-amd64.img --bd-uninstallable-explainer apt
Error reading configuration: PIUPARTS binary 'piuparts' does not exist or is not executable at /usr/share/perl5/Sbuild/Conf.pm line 76.

Now, piuparts is indeed not installed on the host:

  $ apt policy piuparts
  piuparts:
    Installed: (none)
    Candidate: 1.4.1
    Version table:
       1.4.1 800
          800 http://deb.debian.org/debian testing/main amd64 Packages
          500 http://deb.debian.org/debian unstable/main amd64 Packages

However, I thought that setting $run_piuparts = 1 in ~/.sbuildrc caused
piuparts to be run inside the virtual machine guest system, not on the
host system!
Hence, I thought that piuparts was going to be automatically installed
and executed on the guest system (actually on the throw-away overlay).
And I thought that the same was going to happen for $run_autopkgtest = 1
and for $run_lintian = 1 ...

Am I completely off-track?
What did I fail to understand?

Why does sbuild-qemu insist that piuparts be installed on the *host*
system?

Please clarify and/or fix this issue.
Thanks for your kind assistance!

Hi Francesco,

Quoting Francesco Poli (wintermute) (2024-04-11 00:13:51)

I think 1061816 was fixed with 0.85.7 and the changelog was just missing the
"closes" entry:

https://tracker.debian.org/news/1518576/accepted-sbuild-0857-source-into-unstable/

What made you think that? Is the error message above not clear enough? Do you
think it should be improved to make things clearer? Do you have suggestions for
a message that would've better explained that piuparts needs to be installed on
the host system?

Because it needs to be installed on the host. In the same way as autopkgtest
needs to be on the host. What can sbuild improve?

Thanks!

cheers, josch

On Fri, 12 Apr 2024 19:57:23 +0200 Johannes Schauer Marin Rodrigues wrote:

[...]
[...]

Yes, I have just tested sbuild-qemu/0.85.7 from unstable, and I can
confirm that the symlink is no longer needed.
I have just sent a message to close bug report #1061816 ...
[...]
[...]

My point is not that the error message should be improved.
Actually, I think the error message clearness is basically OK.

My point is that sbuild{,-qemu} should install piuparts inside the build
environment (chroot or VM guest system) and run it from within the
build environment, if this is possible.

Does sbuild{,-qemu} do so for lintian? I think this is even more
important for lintian: if the host system runs Debian testing (or maybe
even Debian stable) and the package is being built for Debian unstable
(as upload target), then the package should be checked by the version
of lintian which is currently in Debian unstable. If it were checked by
the version of lintian from Debian testing (or even from Debian
stable), many undeserved "unknown Policy version" complaints could pop
up...

Do you agree with the reasoning?

Thanks for your time and patience!   :-)

know that once you understand how sbuild and piuparts work it becomes
"obvious" that piuparts needs to be run from the host -- but this is not at
all clear for new users: would be great if the documentation and errors
could clearly distinguish between which things inside/outside the chroot


This particular error message could be improved in at least 3 ways:
1. "Error reading configuration" -- suggests it couldnt parse the config
file, which doesnt seem to be the case here (suggest either dropping this
from the error message or saying more clearly what the issue is)

2. "PIUPARTS binary 'piuparts' does not exist or is not executable"

not sure why the capitials and repetition?  just say more directly what the
issue is: eg : "Error: piuparts not found (it needs to be installed on the
host)"

3.  "at /usr/share/perl5/Sbuild/Conf.pm line 76." -- not sure this
implementation detail is helpful for a user -- it makes it look a bug
rather than a message for the user: could it be dropped from the error
message or hidden behind a "debug"/"verbose" setting?


thanks for working on sbuild, it's really great.