$ git clone -n https://src.fedoraproject.org/rpms/luajit.git /var/lib/mock/f41-build-60962209-6586805/root/chroot_tmpdir/scmroot/luajit
Cloning into '/var/lib/mock/f41-build-60962209-6586805/root/chroot_tmpdir/scmroot/luajit'...
$ git fetch origin 35c8e518330ba23c25a95abfcd3fea4a4bf52e3c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/luajit
 * [new ref]         35c8e518330ba23c25a95abfcd3fea4a4bf52e3c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35c8e51 Fix sources