$ git clone -n https://src.fedoraproject.org/rpms/plasma-thunderbolt.git /var/lib/mock/f40-build-794306-139514/root/chroot_tmpdir/scmroot/plasma-thunderbolt
Cloning into '/var/lib/mock/f40-build-794306-139514/root/chroot_tmpdir/scmroot/plasma-thunderbolt'...
$ git fetch origin b516c82af382bdf000efc3af7cbe3b5544974f03:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-thunderbolt
 * [new ref]         b516c82af382bdf000efc3af7cbe3b5544974f03 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b516c82 6.0.2