Bug#1004094: pillow breaks python-imageio autopkgtest: assert (150, 200, 3) == (150, 200, 4)

[Paul Gevers]

Source: pillow, python-imageio
Control: found -1 pillow/9.0.0-1
Control: found -1 python-imageio/2.4.1-3
Severity: serious
Tags: sid bookworm
X-Debbugs-CC: debian-ci at lists.debian.org
User: debian-ci at lists.debian.org
Usertags: breaks needs-update

Dear maintainer(s),

With a recent upload of pillow the autopkgtest of python-imageio fails 
in testing when that autopkgtest is run with the binary packages of 
pillow from unstable. It passes when run with only packages from 
testing. In tabular form:

                        pass            fail
pillow                 from testing    9.0.0-1
python-imageio         from testing    2.4.1-3
all others             from testing    from testing

I copied some of the output at the bottom of this report.

Currently this regression is blocking the migration of pillow to testing 
[1]. Due to the nature of this issue, I filed this bug report against 
both packages. Can you please investigate the situation and reassign the 
bug to the right package?

More information about this bug and the reason for filing it can be found on
https://wiki.debian.org/ContinuousIntegration/RegressionEmailInformation

Paul

[1] https://qa.debian.org/excuses.php?package=pillow

https://ci.debian.net/data/autopkgtest/testing/ppc64el/p/python-imageio/18424529/log.gz

=================================== FAILURES 
===================================
______________________________ test_animated_gif 
_______________________________

     def test_animated_gif():
             # Read newton's cradle
         ims = imageio.mimread("imageio:newtonscradle.gif")
         assert len(ims) == 36
         for im in ims:
>           assert im.shape == (150, 200, 4)
E           assert (150, 200, 3) == (150, 200, 4)
E             At index 2 diff: 3 != 4
E             Full diff:
E             - (150, 200, 4)
E             ?            ^
E             + (150, 200, 3)
E             ?            ^

test_pillow.py:256: AssertionError
=============================== warnings summary 
===============================
test_bsdf.py: 12 warnings
   /usr/lib/python3/dist-packages/imageio/plugins/_bsdf.py:418: 
DeprecationWarning: The 'warn' method is deprecated, use 'warning' instead
     logger.warn("BSDF warning: no extension found for %r" % ext_id)

test_core.py: 4 warnings
test_dicom.py: 2 warnings
test_format.py: 4 warnings
test_grab.py: 2 warnings
   /usr/lib/python3/dist-packages/imageio/core/util.py:562: 
DeprecationWarning: Deprecated since Python 3.4. Use 
importlib.util.find_spec() instead.
     return importlib.find_loader(module_name) is not None

test_pillow.py::test_png
   /usr/lib/python3/dist-packages/imageio/plugins/pillow.py:317: 
UserWarning: PIL PNG writer cannot produce interlaced images.
     warn("PIL PNG writer cannot produce interlaced images.")

-- Docs: https://docs.pytest.org/en/stable/warnings.html
=========================== short test summary info 
============================
FAILED test_pillow.py::test_animated_gif - assert (150, 200, 3) == (150, 
200, 4)
====== 1 failed, 53 passed, 67 skipped, 3 xfailed, 25 warnings in 24.04s 
=======
autopkgtest [08:06:23]: test command1

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