$ git clone -n https://gitee.com/mgb01105731/libcxx.git /var/lib/mock/dist-an23-build-540597-84787/root/chroot_tmpdir/scmroot/libcxx
Cloning into '/var/lib/mock/dist-an23-build-540597-84787/root/chroot_tmpdir/scmroot/libcxx'...
$ git fetch origin 70ee4680674c4ac9d6948233bc2c70d0d995a34b:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/libcxx
 * [new ref]         70ee4680674c4ac9d6948233bc2c70d0d995a34b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 70ee468 Update to 17.0.6