$ git clone -n https://src.fedoraproject.org/rpms/R-packrat.git /var/lib/mock/f40-build-2340164-59697/root/chroot_tmpdir/scmroot/R-packrat
Cloning into '/var/lib/mock/f40-build-2340164-59697/root/chroot_tmpdir/scmroot/R-packrat'...
$ git fetch origin 4632e7464d52e2aa91ba164b03383ab467c8d71c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-packrat
 * [new ref]         4632e7464d52e2aa91ba164b03383ab467c8d71c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4632e74 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild