eyed3 unable to write ID3 v2.2

[mikihau]

Looks like eyed3, the dependent library, refuses to write tags for ID3 v2.2.

To reproduce the issue, download this mp3 file here, create the companion chapters.txt file, then run mp3chaps (any option) on that file. Error message I got:

$ mp3chaps -i ~/Documents/podcasting/final.mp3
Chapters:
Introduction
Chapter Title 1
Chapter Title 2
Traceback (most recent call last):
  File "/Users/mikihau/.virtualenvs/podcast/bin/mp3chaps", line 8, in <module>
    sys.exit(main())
  File "/Users/mikihau/.virtualenvs/podcast/lib/python3.8/site-packages/mp3chaps.py", line 81, in main
    add_chapters(tag, args["<filename>"])
  File "/Users/mikihau/.virtualenvs/podcast/lib/python3.8/site-packages/mp3chaps.py", line 65, in add_chapters
    tag.save()
  File "/Users/mikihau/.virtualenvs/podcast/lib/python3.8/site-packages/eyed3/id3/tag.py", line 900, in save
    raise NotImplementedError("Unable to write ID3 v2.2")
NotImplementedError: Unable to write ID3 v2.2

This happens on macOS Big Sur, pip 20.3.1 from latest release of mp3chaps, with python 3.8.2.

I've heard good things about tagging using mutagen instead -- on README it says "All versions of ID3v2 are supported" so I take it as good sign :)