Comment 2 for bug 1790693

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.