reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux.git/commit/?id=0070c072c1b278f99047ab720e93406ad1359e73
        git remote add boqun https://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux.git
        git fetch --no-tags boqun lockdep-for-tip
        git checkout 0070c072c1b278f99047ab720e93406ad1359e73
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 prepare