[Debian-astro-maintainers] Bug#1040630: gavodachs autopkg tests fail with pillow 10.0.0

[Markus Demleitner]

On Sat, Jul 08, 2023 at 09:23:21AM +0200, Matthias Klose wrote:
> 110s From it/q:
> 110s 	ERROR SCS has a valid response
> 110s 	ERROR TAP query with pgsphere yields plausible result

Interesting -- this fails because the server that's being tested
does not come up because:

  module 'PIL.Image' has no attribute 'ANTIALIAS'

And indeed, it does not:

  >>> from PIL import Image
  >>> Image.ANTIALIAS
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  AttributeError: module 'PIL.Image' has no attribute 'ANTIALIAS'

Now... this seems to be a fairly breaking change (or at least I
suspect there's a lot of code with Image.ANTIALIAS out there).
However, when looking for resize or ANTIALIAS in the upstream
changelog, I don't see it mentioned:
https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst

That made me curious; ANTIALIAS as an alias of LANCZOS was dropped in
upstream commit f8e4e9c2dd94c6f4789639dd891b8a6d5fb16e14 with the
terse commit message "Added enums", where there's this:

  ...
  -LANCZOS = ANTIALIAS = 1

  -_filters_support = {BOX: 0.5, BILINEAR: 1.0, HAMMING: 1.0, BICUBIC: 2.0, LANCZOS: 3.0}
  +# resampling filters (also defined in Imaging.h)
  +class Resampling(IntEnum):
  +    NEAREST = 0
  +    BOX = 4
  +    BILINEAR = 2
  +    HAMMING = 5
  +    BICUBIC = 3
  +    LANCZOS = 1

Whether dropping the widely-documented ANTIALIAS alias was done
deliberately or not I can't say.  And hence I'll not decide whether or
not that's worth an upstream bug.  Instead, I'lljust move to LANCZOS
in DaCHS.

DaCHS users: if you urgently need the package on unstable, please use
our beta repo (https://soft.g-vo.org/repo) for the time being.
Release 2.8 wasn't our best one anyway.  Release 2.9 ought to come
around October-ish anyhow, at which time I'll close this bug (or
should be reminded to close it).