pkg_resources.require() doesn't find soundconverter in flatpak

[Johannes Maibaum]

See downstream issue: https://github.com/flathub/org.soundconverter.SoundConverter/issues/6

A flatpak user noticed that the flatpak on flathub `org.soundconverter.SoundConverter` doesn't launch anymore, but instead `pkg_resources` raises `DistributionNotFound`:

```
[jm@jxps13 ~]$ flatpak run org.soundconverter.SoundConverter
Traceback (most recent call last):
  File "/app/bin/soundconverter", line 36, in <module>
    VERSION = pkg_resources.require('soundconverter')[0].version
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 891, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python3.9/site-packages/pkg_resources/__init__.py", line 777, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'soundconverter' distribution was not found and is required by the application
```

I have looked around, but so far have no idea what change in setuptools (presumably) caused this not working anymore. `soundconverter` is properly installed into `/app/lib/python3.9/site-packages`, and `/app/lib/python3.9/site-packages` is in `sys.path`:

```
[jm@jxps13 ~]$ flatpak run --command=python org.soundconverter.SoundConverter -c 'import sys;print(sys.path)'
['', '/usr/lib/python39.zip', '/usr/lib/python3.9', '/usr/lib/python3.9/lib-dynload', '/usr/lib/python3.9/site-packages', '/app/lib/python3.9/site-packages']
```

Yet, as you can see from my comment on the Github issue, explicitly setting `PYTHONPATH` to `/app/lib/python3.9/site-packages` makes soundconverter launch normally.

I am out of ideas, so I thought I might ask here. Any idea?

[sezanzeb (sezanzeb)]

since pkg_resources is not important for soundconverter to work, I'll try/catch it.

This is actually not the first time I have seen this failing, whatever the reason is

[sezanzeb (sezanzeb)]

oh shit here this is used to figure out where data files are. I'll need to look a bit into it