$ git clone -n https://src.fedoraproject.org/rpms/libxml++.git /var/lib/mock/f39-build-2232973-53353/root/chroot_tmpdir/scmroot/libxml++
Cloning into '/var/lib/mock/f39-build-2232973-53353/root/chroot_tmpdir/scmroot/libxml++'...
$ git fetch origin 242e916f2ec1054f2bf0fa671d9fd85805587ff0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxml++
 * [new ref]         242e916f2ec1054f2bf0fa671d9fd85805587ff0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 242e916 Update to 2.42.3