$ git clone -n https://src.fedoraproject.org/rpms/libpq.git /var/lib/mock/f40-build-2237931-53553/root/chroot_tmpdir/scmroot/libpq
Cloning into '/var/lib/mock/f40-build-2237931-53553/root/chroot_tmpdir/scmroot/libpq'...
$ git fetch origin 629dad748050bf5ae7bdd8f50bcfdee871854b1e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libpq
 * [new ref]         629dad748050bf5ae7bdd8f50bcfdee871854b1e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 629dad7 Update to version 16 Build with ICU support