$ git clone -n https://src.fedoraproject.org/rpms/jaxb-stax-ex.git /var/lib/mock/f40-build-2489803-61655/root/chroot_tmpdir/scmroot/jaxb-stax-ex
Cloning into '/var/lib/mock/f40-build-2489803-61655/root/chroot_tmpdir/scmroot/jaxb-stax-ex'...
$ git fetch origin c9d6403acd38bb7cb9908132bfd2db47cc35a92d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jaxb-stax-ex
 * [new ref]         c9d6403acd38bb7cb9908132bfd2db47cc35a92d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c9d6403 Rebuilt for java-21-openjdk as system jdk