$ git clone -n https://src.fedoraproject.org/rpms/rubygem-hashdiff.git /var/lib/mock/f40-build-2322801-58681/root/chroot_tmpdir/scmroot/rubygem-hashdiff
Cloning into '/var/lib/mock/f40-build-2322801-58681/root/chroot_tmpdir/scmroot/rubygem-hashdiff'...
$ git fetch origin dbf3b387842e9995f1a7cb9f16e98022e2b45cd1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-hashdiff
 * [new ref]         dbf3b387842e9995f1a7cb9f16e98022e2b45cd1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dbf3b38 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild