$ git clone -n https://src.fedoraproject.org/rpms/spectacle.git /var/lib/mock/f42-bootstrap-3533685-46406/root/chroot_tmpdir/scmroot/spectacle
Cloning into '/var/lib/mock/f42-bootstrap-3533685-46406/root/chroot_tmpdir/scmroot/spectacle'...
$ git fetch origin 52ae133ee2095f223aec0678aaf977675b5cbad7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/spectacle
 * [new ref]         52ae133ee2095f223aec0678aaf977675b5cbad7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 52ae133 6.3.5