$ git clone -n https://src.fedoraproject.org/rpms/showtime.git /var/lib/mock/f42-build-3272213-41305/root/chroot_tmpdir/scmroot/showtime
Cloning into '/var/lib/mock/f42-build-3272213-41305/root/chroot_tmpdir/scmroot/showtime'...
$ git fetch origin 8f350ac5d755d3eca4806c18d3d22a9bf40ab22c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/showtime
 * [new ref]         8f350ac5d755d3eca4806c18d3d22a9bf40ab22c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8f350ac Update to 48.beta.1