$ git clone -n https://src.fedoraproject.org/rpms/byzanz.git /var/lib/mock/f40-build-2291014-56010/root/chroot_tmpdir/scmroot/byzanz
Cloning into '/var/lib/mock/f40-build-2291014-56010/root/chroot_tmpdir/scmroot/byzanz'...
$ git fetch origin 2c4b713bc81c01d989464d3eee76e5dd15ba1297:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/byzanz
 * [new ref]         2c4b713bc81c01d989464d3eee76e5dd15ba1297 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2c4b713 Orphaned for 6+ weeks