$ git clone -n https://src.fedoraproject.org/rpms/openmsx.git /var/lib/mock/f45-build-21068-578/root/chroot_tmpdir/scmroot/openmsx
Cloning into '/var/lib/mock/f45-build-21068-578/root/chroot_tmpdir/scmroot/openmsx'...
$ git fetch origin 3bd29edf2bf95c644f7891f1c98e2bd49f461d46:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openmsx
 * [new ref]         3bd29edf2bf95c644f7891f1c98e2bd49f461d46 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3bd29ed Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild