$ git clone -n https://src.fedoraproject.org/rpms/R-FMStable.git /var/lib/mock/f41-build-side-1-3142755-40009/root/chroot_tmpdir/scmroot/R-FMStable
Cloning into '/var/lib/mock/f41-build-side-1-3142755-40009/root/chroot_tmpdir/scmroot/R-FMStable'...
$ git fetch origin f35028f6899cbe186ef981bb4d8d78cac38897d1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-FMStable
 * [new ref]         f35028f6899cbe186ef981bb4d8d78cac38897d1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f35028f convert GPLv3 license to SPDX