$ git clone -n https://src.fedoraproject.org/rpms/gnome-calendar.git /var/lib/mock/f39-build-1668613-40832/root/chroot_tmpdir/scmroot/gnome-calendar
Cloning into '/var/lib/mock/f39-build-1668613-40832/root/chroot_tmpdir/scmroot/gnome-calendar'...
$ git fetch origin 270a6120887d1e931cb87542e7055481399c6701:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-calendar
 * [new ref]         270a6120887d1e931cb87542e7055481399c6701 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 270a612 Update to 45.1