Seems fixed upstream: https://bitbucket.org/McKael/mcabber-crew/commits/3385a4bb62efa71bb522ebd6e5f57c49e22a72e4
It doesn't really matter now, but I said that the empty string can deactivate the option and that is not true. It must be *unset* (never set or explicitly unset). set disable_random_resource = "" # set to the empty string; "settings_opt_get" returns non-null pointer set disable_random_resource = # unset; "settings_opt_get" returns null