$ git clone -n https://gitee.com/llvm-la/clang.git /var/lib/mock/dist-an23.2-build-402539-72394/root/chroot_tmpdir/scmroot/clang
Cloning into '/var/lib/mock/dist-an23.2-build-402539-72394/root/chroot_tmpdir/scmroot/clang'...
$ git fetch origin b89f5bc77b8a55fb1a2a0d2e4b240e134d2fcb4d:KOJI_FETCH_HEAD
From https://gitee.com/llvm-la/clang
 * [new ref]         b89f5bc77b8a55fb1a2a0d2e4b240e134d2fcb4d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b89f5bc [Feature] Backport some patches from upstream on LoongArch