$ git clone -n https://src.fedoraproject.org/rpms/R-simmer.git /var/lib/mock/f39-build-2020672-46545/root/chroot_tmpdir/scmroot/R-simmer
Cloning into '/var/lib/mock/f39-build-2020672-46545/root/chroot_tmpdir/scmroot/R-simmer'...
$ git fetch origin 0c6b374d441151f4fd3ea37527af4823be5065ae:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-simmer
 * [new ref]         0c6b374d441151f4fd3ea37527af4823be5065ae -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0c6b374 Update to 4.4.6.3