$ git clone -n https://src.fedoraproject.org/rpms/libva.git /var/lib/mock/f40-build-2672830-67555/root/chroot_tmpdir/scmroot/libva
Cloning into '/var/lib/mock/f40-build-2672830-67555/root/chroot_tmpdir/scmroot/libva'...
$ git fetch origin 3ad3e61df118ad7a95eec9a273aa40b655391b3e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libva
 * [new ref]         3ad3e61df118ad7a95eec9a273aa40b655391b3e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3ad3e61 Rebuilt