$ git clone -n https://src.fedoraproject.org/rpms/postgresql-jdbc.git /var/lib/mock/f40-build-2601369-63189/root/chroot_tmpdir/scmroot/postgresql-jdbc
Cloning into '/var/lib/mock/f40-build-2601369-63189/root/chroot_tmpdir/scmroot/postgresql-jdbc'...
$ git fetch origin a890886e2017dd33364a475917ef9989a6b87ad4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/postgresql-jdbc
 * [new ref]         a890886e2017dd33364a475917ef9989a6b87ad4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a890886 rebase to upstream version 42.7.3