$ git clone -n https://src.fedoraproject.org/rpms/R-generics /var/lib/mock/f39-build-1583914-38129/root/chroot_tmpdir/scmroot/R-generics
Cloning into '/var/lib/mock/f39-build-1583914-38129/root/chroot_tmpdir/scmroot/R-generics'...
$ git fetch origin 85d345b477b96a2bb5fb47347df397e9673457dc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-generics
 * [new ref]         85d345b477b96a2bb5fb47347df397e9673457dc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85d345b Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild