$ git clone -n https://src.fedoraproject.org/rpms/libburn.git /var/lib/mock/f41-build-1045124-19054/root/chroot_tmpdir/scmroot/libburn
Cloning into '/var/lib/mock/f41-build-1045124-19054/root/chroot_tmpdir/scmroot/libburn'...
$ git fetch origin dfa992ddb3d1a82ac3e3e1fa0498261c37cdb8dd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libburn
 * [new ref]         dfa992ddb3d1a82ac3e3e1fa0498261c37cdb8dd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dfa992d Spec file cleanup, modernization and unification