reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git/commit/?id=e7295d8301c4d643fec9ff2988ac861c4b0e77f0
        git remote add pcmoore-lsm https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git
        git fetch --no-tags pcmoore-lsm main
        git checkout e7295d8301c4d643fec9ff2988ac861c4b0e77f0
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs