Comment 22 for bug 1824000

I'm affected as well.

Running Ubuntu 20.04, fully updated.

First noticed today when 'thefuck' stopped working. Confirmed that other "unknown" commands trigger this.

$ foobar
Sorry, command-not-found has crashed! Please file a bug report at:
https://bugs.launchpad.net/command-not-found/+filebug
Please include the following information with the report:

command-not-found version: 0.3
Python version: 3.8.5 final 0
Distributor ID: Ubuntu
Description: Ubuntu 20.04.2 LTS
Release: 20.04
Codename: focal
Exception information:

unable to open database file
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/CommandNotFound/util.py", line 23, in crash_guard
    callback()
  File "/usr/lib/command-not-found", line 90, in main
    cnf = CommandNotFound.CommandNotFound(options.data_dir)
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 79, in __init__
    self.db = SqliteDatabase(dbpath)
  File "/usr/lib/python3/dist-packages/CommandNotFound/db/db.py", line 12, in __init__
    self.con = sqlite3.connect(filename)
sqlite3.OperationalError: unable to open database file

Confirmed that the issue is the permissions, running "chmod" as per comment 2 fixed it.