$ git clone -n https://src.fedoraproject.org/rpms/aggregate6.git /var/lib/mock/f41-build-side-1-2771915-32257/root/chroot_tmpdir/scmroot/aggregate6
Cloning into '/var/lib/mock/f41-build-side-1-2771915-32257/root/chroot_tmpdir/scmroot/aggregate6'...
$ git fetch origin 7f233a43af3249989bc130eb600b51f3fa6ed351:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/aggregate6
 * [new ref]         7f233a43af3249989bc130eb600b51f3fa6ed351 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7f233a4 Remove EPEL 7 build-time support