$ git clone -n https://src.fedoraproject.org/rpms/lxmusic.git /var/lib/mock/f41-build-847434-163983/root/chroot_tmpdir/scmroot/lxmusic
Cloning into '/var/lib/mock/f41-build-847434-163983/root/chroot_tmpdir/scmroot/lxmusic'...
$ git fetch origin 89309c1f98c7d2a5edb449642575c6d11df9303a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lxmusic
 * [new ref]         89309c1f98c7d2a5edb449642575c6d11df9303a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 89309c1 update source