reproduce:
        # https://github.com/bvanassche/linux/commit/834588da5a3bc2696586cdc98024dcebec97aeed
        git remote add bvanassche https://github.com/bvanassche/linux
        git fetch --no-tags bvanassche thread-safety
        git checkout 834588da5a3bc2696586cdc98024dcebec97aeed
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs