$ git clone -n https://src.fedoraproject.org/rpms/R.git /var/lib/mock/f41-build-1692587-24354/root/chroot_tmpdir/scmroot/R
Cloning into '/var/lib/mock/f41-build-1692587-24354/root/chroot_tmpdir/scmroot/R'...
$ git fetch origin b1986676d4ce8985ea0e117cc59f047501380209:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R
 * [new ref]         b1986676d4ce8985ea0e117cc59f047501380209 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b198667 Add less back as default PAGER