$ git clone -n https://gitee.com/opencloudos-stream/llvm12.git /var/lib/mock/dist-ocs23-epol9-build-214958-16010/root/chroot_tmpdir/scmroot/llvm12
Cloning into '/var/lib/mock/dist-ocs23-epol9-build-214958-16010/root/chroot_tmpdir/scmroot/llvm12'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/llvm12
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f575e58 update