Beets: during pluginload ... Name node can't be used with 'None' constant

[rmNULL]

Problem

running beet <any command> crashes

ValueError: Name node can't be used with 'None' constant

Running this command in verbose (-vv) mode:

$ beet -vv help

Led to this problem:

user configuration: /home/rmnull/.config/beets/config.yaml
data directory: /home/rmnull/.config/beets
plugin paths: 
Sending event: pluginload
Traceback (most recent call last):
  File "/home/rmnull/.local/bin/beet", line 8, in <module>
    sys.exit(main())
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/ui/__init__.py", line 1266, in main
    _raw_main(args)
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/ui/__init__.py", line 1249, in _raw_main
    subcommands, plugins, lib = _setup(options, lib)
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/ui/__init__.py", line 1144, in _setup
    lib = _open_library(config)
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/ui/__init__.py", line 1201, in _open_library
    get_path_formats(),
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/ui/__init__.py", line 619, in get_path_formats
    path_formats.append((query, template(view.as_str())))
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/util/functemplate.py", line 571, in template
    return Template(fmt)
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/util/functemplate.py", line 581, in __init__
    self.compiled = self.translate()
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/util/functemplate.py", line 614, in translate
    func = compile_func(
  File "/home/rmnull/.local/lib/python3.8/site-packages/beets/util/functemplate.py", line 155, in compile_func
    prog = compile(mod, '<generated>', 'exec')
ValueError: Name node can't be used with 'None' constant

Here's a link to the music files that trigger the bug (if relevant):

Setup

• OS: Linux eos 5.7.9_1 #1 SMP Thu Jul 16 10:02:50 UTC 2020 x86_64 GNU/Linux
• Python version: 3.8.4
• beets version: 1.4.9(referred from pip list, beet --version crashes)
• Turning off plugins made problem go away (yes/no): no

My configuration (output of beet config) is:
beet config crashes with the same error mentioned above.
However beet config -e works fine

directory: /tmp/Music/
library: /tmp/Music/beets_library.db
import:
  move: no

Other Notes

The problem persists on reinstall
sh $ pip3 uninstall beets $ pip3 install beets $ beet help # same crash

I don't see this as a problem in beets,
There was no problem installing beets in docker.
Clarification: Asking it as a question to have this issue resolved rather than pointing it as bug in beets.

[wisp3rwind]

See https://github.com/beetbox/beets/pull/3621 and https://github.com/beetbox/beets/issues/3625

[rmNULL]

@wisp3rwind thanks

[noodle-]

Any workaround while we wait for the next release?

[jackwilsdon]

Running the latest source version of beets is probably the simplest option for the time being.

[AssenD]

64bit W10, 64bit Py3.9.0, beets version 1.4.9 - same problem

[jackwilsdon]

@AssenD please see #3621 and #3625 (as mentioned in this comment).

[davidheijkamp]

A simple workaround on my Ubuntu machine was to force a specific version of python by changing the shebang in ~/.local/bin/beet from:

#!/usr/bin/python3

to:

#!/usr/bin/python3.6

Probably 3.7 would work as well, if that version of Python is installed on your machine.

[wisp3rwind]

Probably 3.7 would work as well, if that version of Python is installed on your machine.

Yeah, most likely, the relevant Python change wasn't backported to 3.7 as far as I can tell.