$ git clone -n https://src.fedoraproject.org/rpms/mlpack.git /var/lib/mock/f41-build-side-2-python-2708462-30473/root/chroot_tmpdir/scmroot/mlpack
Cloning into '/var/lib/mock/f41-build-side-2-python-2708462-30473/root/chroot_tmpdir/scmroot/mlpack'...
$ git fetch origin 428a5732ab40a8f09ec4d93ddf8f8c742c84b1a2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mlpack
 * [new ref]         428a5732ab40a8f09ec4d93ddf8f8c742c84b1a2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 428a573 Update to latest stable version.