$ git clone -n https://src.fedoraproject.org/rpms/xsd.git /var/lib/mock/f42-build-862912-171231/root/chroot_tmpdir/scmroot/xsd
Cloning into '/var/lib/mock/f42-build-862912-171231/root/chroot_tmpdir/scmroot/xsd'...
$ git fetch origin 77e736049c0406ee4d84676fff048bc67d50d443:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xsd
 * [new ref]         77e736049c0406ee4d84676fff048bc67d50d443 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77e7360 Rebuild for xerces-c 3.3