I modified /etc/apt/apt.conf.d/50appstream so it'd log to a file and provide more details e.g.
# Refresh AppStream cache when APT's cache is updated (i.e. apt update) APT::Update::Post-Invoke-Success { "if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh-cache --verbose > /tmp/appstream-cli.log; fi"; }; Attached is the appstream-cli.log file. ** Attachment added: "appstream-cli.log" https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1790693/+attachment/5184591/+files/appstream-cli.log ** Also affects: appstream (Ubuntu) Importance: Undecided Status: New ** Changed in: appstream (Ubuntu) Importance: Undecided => High ** Tags added: rls-cc-incoming -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1790693 Title: appstreamcli crash when attempting release upgrade to cosmic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/appstream/+bug/1790693/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs