$ git clone -n https://src.fedoraproject.org/rpms/libxshmfence.git /var/lib/mock/f45-build-17318-498/root/chroot_tmpdir/scmroot/libxshmfence
Cloning into '/var/lib/mock/f45-build-17318-498/root/chroot_tmpdir/scmroot/libxshmfence'...
$ git fetch origin 128c73a67b2a61cf0239e521d6f0a525baf63133:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxshmfence
 * [new ref]         128c73a67b2a61cf0239e521d6f0a525baf63133 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 128c73a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild