$ git clone -n https://src.fedoraproject.org/forks/catme0w/rpms/R-pkgload /var/lib/mock/f41-build-side-1-3148575-40058/root/chroot_tmpdir/scmroot/R-pkgload
Cloning into '/var/lib/mock/f41-build-side-1-3148575-40058/root/chroot_tmpdir/scmroot/R-pkgload'...
$ git fetch origin 842882eab7028096db087dc9d0dd94804b2237bb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/catme0w/rpms/R-pkgload
 * [new ref]         842882eab7028096db087dc9d0dd94804b2237bb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 842882e Update R-pkgload.spec