The "test-var-list" command:

Usage: fossil test-var-list ?PATTERN? ?--unset? ?--mtime?

Show the content of the CONFIG table in a repository.  If PATTERN is
specified, then only show the entries that match that glob pattern.
Last modification time is shown if the --mtime option is present.

If the --unset option is included, then entries are deleted rather than
being displayed.  WARNING! This cannot be undone.  Be sure you know what
you are doing!  The --unset option only works if there is a PATTERN.
Probably you should run the command once without --unset to make sure
you know exactly what is being deleted.

If not in an open check-out, use the -R REPO option to specify a
a repository.