$ git clone -n https://src.fedoraproject.org/rpms/R-systemfit.git /var/lib/mock/f41-build-side-1-2631118-25666/root/chroot_tmpdir/scmroot/R-systemfit
Cloning into '/var/lib/mock/f41-build-side-1-2631118-25666/root/chroot_tmpdir/scmroot/R-systemfit'...
$ git fetch origin 33945f1911fcd11130578e0f58444a79755d3c9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-systemfit
 * [new ref]         33945f1911fcd11130578e0f58444a79755d3c9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 33945f1 convert GPLv2+ license to SPDX