Comment 0 for bug 1876034

On all Ubuntu releases since at least 19.10, enabling compressed APT package list storage with command-not-found installed leads to this crash in the cnf-update-db hook called by apt update:

Traceback (most recent call last):
  File "/usr/lib/cnf-update-db", line 26, in <module>
    col.create(db)
  File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 93, in create
    self._fill_commands(con)
  File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 127, in _fill_commands
    self._parse_single_commands_file(con, fp)
  File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 165, in _parse_single_commands_file
    suite=tagf.section["suite"]
KeyError: 'suite'

(To enable compressed APT list storage, add Acquire::GzipIndexes "true"; to an apt.conf fragment.)

This appears to be caused by apt downloading an lz4-compressed command list for command-not-found and cnf-update-db passing the /var/lib/apt/lists/*Commands-*.lz4 files to db/creator.py, which does not know about the compression and attempts to parse them as plain text.