using the plugin with Pillow (used by sigal, static image gallery generator ) it crashes:

[Simon566]

Describe the bug

using the plugin with Pillow (used by sigal, static image gallery generator ) it crashes:

Collecting albums, done.
  Sorting albums  [####################################]  100%
   Sorting media  [####################################]  100%
Collecting files  [####################################]  100%
Processing files  [------------------------------------]  0/2
Traceback (most recent call last):
  File "/home/simon/python_virt_sigal/env/bin/sigal", line 8, in <module>
    sys.exit(main())
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/click/core.py", line 1128, in __call__
    return self.main(*args, **kwargs)
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/click/core.py", line 1053, in main
    rv = self.invoke(ctx)
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/click/core.py", line 1659, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/click/core.py", line 1395, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/click/core.py", line 754, in invoke
    return __callback(*args, **kwargs)
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/sigal/__init__.py", line 157, in build
    gal.build(force=force)
  File "/home/simon/python_virt_sigal/env/lib/python3.9/site-packages/sigal/gallery.py", line 756, in build
    for status in self.pool.imap_unordered(worker, media_list):
  File "/usr/lib/python3.9/multiprocessing/pool.py", line 870, in next
    raise value
  File "/usr/lib/python3.9/multiprocessing/pool.py", line 537, in _handle_tasks
    put(task)
  File "/usr/lib/python3.9/multiprocessing/connection.py", line 211, in send
    self._send_bytes(_ForkingPickler.dumps(obj))
  File "/usr/lib/python3.9/multiprocessing/reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
TypeError: cannot pickle 'module' object

i do generate image gallery with sigal, which uses Pillow

i do generate image gallery with sigal, which uses Pillow

Expected behavior

Pillow can handle heif images with this plugin and the gallery generates

Code / screenshots

Environment

• Library version:
• Language/framework version:
• OS version: