$ git clone -n https://src.fedoraproject.org/rpms/R-generics.git /var/lib/mock/f45-build-6133-346/root/chroot_tmpdir/scmroot/R-generics
Cloning into '/var/lib/mock/f45-build-6133-346/root/chroot_tmpdir/scmroot/R-generics'...
$ git fetch origin be3666956dfaf6f5a6ad65dcee40c6df8ab1659c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-generics
 * [new ref]         be3666956dfaf6f5a6ad65dcee40c6df8ab1659c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at be36669 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild