$ git clone -n https://src.fedoraproject.org/rpms/R-quantities.git /var/lib/mock/f38-build-724250-99404/root/chroot_tmpdir/scmroot/R-quantities
Cloning into '/var/lib/mock/f38-build-724250-99404/root/chroot_tmpdir/scmroot/R-quantities'...
$ git fetch origin 435c00bf26416cf091add59dc069af356cbf549f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-quantities
 * [new ref]         435c00bf26416cf091add59dc069af356cbf549f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 435c00b Update to 0.2.1