reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/89dfe1bb90b6b8ee0de6f320cc97fa18aff2d6f0
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Daniel-Palmer/tools-nolibc-Add-sendfile/20260828-193204
        git checkout 89dfe1bb90b6b8ee0de6f320cc97fa18aff2d6f0
        # apt-get install llvm-dev

        # save the config file
        make W=1 ARCH=i386 olddefconfig
        make W=1 ARCH=i386 
        make W=1 headers_install
        make W=1 -C tools/testing/selftests