$ git clone -n https://src.fedoraproject.org/rpms/openshadinglanguage.git /var/lib/mock/f40-build-803344-144233/root/chroot_tmpdir/scmroot/openshadinglanguage
Cloning into '/var/lib/mock/f40-build-803344-144233/root/chroot_tmpdir/scmroot/openshadinglanguage'...
$ git fetch origin 5ad80c9fdfb424f802f11c8ab7aa37d113198e7c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/openshadinglanguage
 * [new ref]         5ad80c9fdfb424f802f11c8ab7aa37d113198e7c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5ad80c9 Fix busted Release value