$ git clone -n https://src.fedoraproject.org/rpms/atomic-reactor.git /var/lib/mock/f41-build-762739-13458/root/chroot_tmpdir/scmroot/atomic-reactor
Cloning into '/var/lib/mock/f41-build-762739-13458/root/chroot_tmpdir/scmroot/atomic-reactor'...
$ git fetch origin c8f28a851b4ececdbc8c1b6ddcb4f3f46e7fa0aa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/atomic-reactor
 * [new ref]         c8f28a851b4ececdbc8c1b6ddcb4f3f46e7fa0aa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c8f28a8 Eliminate use of obsolete %patchN syntax (#2283636)