$ git clone -n https://src.fedoraproject.org/rpms/plasma-vault.git /var/lib/mock/f42-bootstrap-3533989-46428/root/chroot_tmpdir/scmroot/plasma-vault
Cloning into '/var/lib/mock/f42-bootstrap-3533989-46428/root/chroot_tmpdir/scmroot/plasma-vault'...
$ git fetch origin 78e27e9a2713ff8e2daceec46c72f1b90bcdd17f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-vault
 * [new ref]         78e27e9a2713ff8e2daceec46c72f1b90bcdd17f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 78e27e9 6.3.5