fetchart: permissions errors result in a crash, needs graceful fallback

[henry-oberholtzer]

Problem

I think this is caused by my foorbar2000 instance checking the folder, regardless, fetchart should have a more graceful fallback in this situation.

Led to this problem:

Traceback (most recent call last):
  File "C:\Python312\Lib\site-packages\beets\util\__init__.py", line 504, in move
    os.replace(syspath(path), syspath(dest))
OSError: [WinError 17] The system cannot move the file to a different disk drive: '\\\\?\\C:\\Users\\Henry\\AppData\\Local\\Temp\\beets\\beetsplug_fetchart\\2svf0w77.jpg' -> '\\\\?\\E:\\Media Library\\Music\\Digital\\e\\Ed Rush & Optical\\Travel the Galaxy (2009, Virus Recordings VRS007DD) [FLAC 16-44]\\cover.jpg'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Python312\Lib\site-packages\beets\util\__init__.py", line 537, in move
    os.replace(tmp_filename, syspath(dest))
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: '\\\\?\\E:\\Media Library\\Music\\Digital\\e\\Ed Rush & Optical\\Travel the Galaxy (2009, Virus Recordings VRS007DD) [FLAC 16-44]\\.cover.jpg.jtsvsidc.beets' -> '\\\\?\\E:\\Media Library\\Music\\Digital\\e\\Ed Rush & Optical\\Travel the Galaxy (2009, Virus Recordings VRS007DD) [FLAC 16-44]\\cover.jpg'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Python312\Lib\site-packages\beets\util\__init__.py", line 541, in move
    raise FilesystemError(
beets.util.FilesystemError: The process cannot access the file because it is being used by another process while moving C:\Users\Henry\AppData\Local\Temp\beets\beetsplug_fetchart\2svf0w77.jpg to E:\Media Library\Music\Digital\e\Ed Rush & Optical\Travel the Galaxy (2009, Virus Recordings VRS007DD) [FLAC 16-44]\cover.jpg

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Python312\Scripts\beet.exe\__main__.py", line 7, in <module>
  File "C:\Python312\Lib\site-packages\beets\ui\__init__.py", line 1635, in main
    _raw_main(args)
  File "C:\Python312\Lib\site-packages\beets\ui\__init__.py", line 1614, in _raw_main
    subcommand.func(lib, suboptions, subargs)
  File "C:\Python312\Lib\site-packages\beets\ui\commands\import_\__init__.py", line 131, in import_func
    import_files(lib, byte_paths, query)
  File "C:\Python312\Lib\site-packages\beets\ui\commands\import_\__init__.py", line 75, in import_files
    session.run()
  File "C:\Python312\Lib\site-packages\beets\importer\session.py", line 236, in run
    pl.run_parallel(QUEUE_SIZE)
  File "C:\Python312\Lib\site-packages\beets\util\pipeline.py", line 471, in run_parallel
    raise exc_info[1].with_traceback(exc_info[2])
  File "C:\Python312\Lib\site-packages\beets\util\pipeline.py", line 383, in run
    self.coro.send(msg)
  File "C:\Python312\Lib\site-packages\beets\util\pipeline.py", line 195, in coro
    task = func(*(args + (task,)))
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python312\Lib\site-packages\beets\importer\stages.py", line 299, in manipulate_files
    task.manipulate_files(
  File "C:\Python312\Lib\site-packages\beets\importer\tasks.py", line 490, in manipulate_files
    plugins.send("import_task_files", session=session, task=self)
  File "C:\Python312\Lib\site-packages\beets\plugins.py", line 639, in send
    if (r := handler(**arguments)) is not None
             ^^^^^^^^^^^^^^^^^^^^
  File "C:\Python312\Lib\site-packages\beets\plugins.py", line 329, in wrapper
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python312\Lib\site-packages\beetsplug\fetchart.py", line 1480, in assign_art
    self._set_art(task.album, candidate, not removal_enabled)
  File "C:\Python312\Lib\site-packages\beetsplug\fetchart.py", line 1464, in _set_art
    album.set_art(candidate.path, delete)
  File "C:\Python312\Lib\site-packages\beets\library\models.py", line 565, in set_art
    util.move(path, artdest)
  File "C:\Python312\Lib\site-packages\beets\util\__init__.py", line 546, in move
    os.remove(tmp_filename)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: '\\\\?\\E:\\Media Library\\Music\\Digital\\e\\Ed Rush & Optical\\Travel the Galaxy (2009, Virus Recordings VRS007DD) [FLAC 16-44]\\.cover.jpg.jtsvsidc.beets'