I'm also affected by this bug. The following lines from journalctl appear to be relevant - PackageKit crashes like this every time gnome-software is started.
Jan 17 02:27:03 Melchior-2 dbus-daemon[870]: [session uid=1000 pid=870] Activating service name='org.gnome.Software' requested by ':1.10' (uid=1000 pi Jan 17 02:27:03 Melchior-2 dbus-daemon[870]: [session uid=1000 pid=870] Successfully activated service 'org.gnome.Software' Jan 17 02:27:06 Melchior-2 gnome-software[1660]: plugin appstream took 3,0 seconds to do setup Jan 17 02:27:06 Melchior-2 gnome-software[1660]: enabled plugins: desktop-categories, fwupd, os-release, packagekit, packagekit-local, packagekit-offl Jan 17 02:27:06 Melchior-2 gnome-software[1660]: disabled plugins: dpkg, dummy, repos, epiphany Jan 17 02:27:06 Melchior-2 dbus-daemon[494]: [system] Activating via systemd: service name='org.freedesktop.PackageKit' unit='packagekit.service' requ Jan 17 02:27:06 Melchior-2 systemd[1]: Starting PackageKit Daemon... Jan 17 02:27:06 Melchior-2 PackageKit[1666]: daemon start Jan 17 02:27:06 Melchior-2 dbus-daemon[494]: [system] Successfully activated service 'org.freedesktop.PackageKit' Jan 17 02:27:06 Melchior-2 systemd[1]: Started PackageKit Daemon. Jan 17 02:27:06 Melchior-2 PackageKit[1666]: uid 1000 is trying to obtain org.freedesktop.packagekit.system-sources-refresh auth (only_trusted:0) Jan 17 02:27:06 Melchior-2 PackageKit[1666]: uid 1000 obtained auth for org.freedesktop.packagekit.system-sources-refresh Jan 17 02:27:10 Melchior-2 packagekitd[1666]: terminate called after throwing an instance of 'std::length_error' Jan 17 02:27:10 Melchior-2 packagekitd[1666]: what(): basic_string::_M_replace Jan 17 02:27:10 Melchior-2 systemd[1]: packagekit.service: Main process exited, code=killed, status=6/ABRT Jan 17 02:27:10 Melchior-2 systemd[1]: packagekit.service: Failed with result 'signal'.
