$ git clone -n https://src.fedoraproject.org/rpms/R-packrat.git /var/lib/mock/f40-build-2182424-51174/root/chroot_tmpdir/scmroot/R-packrat
Cloning into '/var/lib/mock/f40-build-2182424-51174/root/chroot_tmpdir/scmroot/R-packrat'...
$ git fetch origin 6b2fba0624f547f0205cb0bef3001ca5f595dfe4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-packrat
 * [new ref]         6b2fba0624f547f0205cb0bef3001ca5f595dfe4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6b2fba0 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild