$ git clone -n https://gitee.com/src-opencloudos-rpms/eigen3.git /var/lib/mock/dist-oc9-build-127037-76437/root/chroot_tmpdir/scmroot/eigen3
Cloning into '/var/lib/mock/dist-oc9-build-127037-76437/root/chroot_tmpdir/scmroot/eigen3'...
$ git fetch origin oc9:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/eigen3
 * [new branch]      oc9        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 80eb0b9 import eigen3-3.4.0-6.tl4