$ git clone -n https://src.fedoraproject.org/rpms/R-simmer /var/lib/mock/f41-build-side-1-3149125-40244/root/chroot_tmpdir/scmroot/R-simmer
Cloning into '/var/lib/mock/f41-build-side-1-3149125-40244/root/chroot_tmpdir/scmroot/R-simmer'...
$ git fetch origin d04ea7ed84241ce2938cbcbff146ff1a37a632bb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-simmer
 * [new ref]         d04ea7ed84241ce2938cbcbff146ff1a37a632bb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d04ea7e Update to 4.4.7