#1110102 sbuild cannot find 'qemu' in --chroot-mode=autopkgtest

Package:
sbuild
Source:
sbuild
Submitter:
Christian Kastner
Date:
2025-08-10 14:43:01 UTC
Severity:
normal
#1110102#5
Date:
2025-07-29 20:34:30 UTC
From:
To:
On trixie, with --chroot-mode=autopkgtest, something seems to have
happened in the virt server lookup for 'qemu'. The real command
'autopkgtest-virt-qemu' is no longer found:

  # Can be run in any directory to reproduce the error
  $ sbuild -d unstable --chroot-mode=autopkgtest --autopkgtest-virt-server=qemu sbuild

  +==============================================================================+
  | sbuild (amd64)                               Tue, 29 Jul 2025 20:13:11 +0000 |
  +==============================================================================+

  Package: sbuild
  Distribution: unstable
  Machine Architecture: amd64
  Host Architecture: amd64
  Build Architecture: amd64
  Build Type: binary

  Can't exec "qemu": No such file or directory at /usr/share/perl5/Sbuild/ChrootAutopkgtest.pm line 94.
              ^^^^

When using --autopkgtest-virt-server=autopkgtest-virt-qemu, the issue
seems to be resolved. However, the man page says to use the short name.

I have no clue what could have caused this, and I cannot reproduce this
with the 0.88.4 packages (I was using those on bookworm before my upgrade).

I'd appreciate it if someone could try to reproduce this.

Best,
Christian
#1110102#10
Date:
2025-07-30 11:51:30 UTC
From:
To:
Hi Christian,

* Christian Kastner <ckk@debian.org> [2025-07-29 22:34]:

I reproduced this, though the last working version is 0.88.1 for me.
More specifically 2dcaaca2 is the commit changing the behaviour.

The problem is that CHECK in AUTOPKGTEST_VIRT_SERVER tests against the
DEFAULT value, not the value from the command line. This seems to be e
general problem but I don't have enough Perl knowledge to fix this.

Cheers Jochen
#1110102#15
Date:
2025-07-30 19:44:18 UTC
From:
To:
Hi Jochen,

Thank you very much for reproducing!

Hm, it's possible that I might not have used sbuild-qemu much recently,
as the unshare backend was much more convenient for my ROCm work, and I
didn't need full isolation.

Sadly, me neither :)

Best,
Christian
#1110102#20
Date:
2025-08-10 14:42:12 UTC
From:
To:
wall.

I did find the code [1] where the 'qemu' shortname should have been
converted to 'autopkgtest-virt-qemu', resp. same thing for all the other
backends.

Suspicion: could it be that the changes of 2dcaaca2 or 7e4c1404 no
longer trigger the above code path at the right time?

Best,
Christian

[1]: https://salsa.debian.org/debian/sbuild/-/blob/54766f522630b15f36bf1f0bbf1c3c4e473bc2a9/lib/Sbuild/Conf.pm#L455