$ git clone -n https://src.fedoraproject.org/rpms/xerces-j2.git /var/lib/mock/f40-build-2648109-66751/root/chroot_tmpdir/scmroot/xerces-j2
Cloning into '/var/lib/mock/f40-build-2648109-66751/root/chroot_tmpdir/scmroot/xerces-j2'...
$ git fetch origin b0c18cf9b98b60835e5aca81b56792f3075cc795:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xerces-j2
 * [new ref]         b0c18cf9b98b60835e5aca81b56792f3075cc795 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b0c18cf Rebuilt for java-21-openjdk as system jdk