$ git clone -n https://src.fedoraproject.org/rpms/postgresql-jdbc.git /var/lib/mock/f38-build-side-42-init-devel-628808-26374/root/chroot_tmpdir/scmroot/postgresql-jdbc
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-628808-26374/root/chroot_tmpdir/scmroot/postgresql-jdbc'...
$ git fetch origin a3ce18cf842ddb9be08097d834f04d41a027f82c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/postgresql-jdbc
 * [new ref]         a3ce18cf842ddb9be08097d834f04d41a027f82c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a3ce18c rebase to 42.5.2