[Python-modules-team] Bug#954471: src:pystemd: Autopkgtest failure due to use of py3versions -iwq

[Scott Kitterman]

Package: src:pystemd
Version: 0.7.0-2
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)

Note: Using the FTBFS tag because it's the closest we have.

This package failed a recent autopkgtest and this is one of the blockers for
python3-defaults migration.  It failed because python3.7 was installed in the
chroot and the current autopkgtest doesn't handle that.

Autopkgtests should be run for all supported versions.  The package attempts
to do that, but in a way that is unreliable.

Based on a review of the failure log (I have not looked at the package, so
there's a small chance the root cause is different), the autopkgtest uses the
output of py3versions -i to iterate over available python3 versions.  The -i
flag indicates all installed versions.  In many cases python3.7 is still
partially installed, so it is included in the tests, but fails.

The reliable way to do this is add python3-all to your tests depends in
debian/tests/control and change the py3versions call to py3versions -s.  These
two steps will ensure all supported python3 interpreters are fully installed
and that the tests are run against them.

As this is a blocker for getting python3.8 as default python3 into bullseye,
please address this soon.  I'm open to doing NMUs if anyone would like the
support.  Please let me know if you would like for me to do that.

Scott K