$ git clone -n https://gitee.com/fundawang/libcxx.git /var/lib/mock/dist-an23-build-265094-63990/root/chroot_tmpdir/scmroot/libcxx
Cloning into '/var/lib/mock/dist-an23-build-265094-63990/root/chroot_tmpdir/scmroot/libcxx'...
$ git reset --hard 6b97d6b8b1a360ee0b0f6a618239ed0244cf3bf9
HEAD is now at 6b97d6b 16.0.4