reproduce (this is a W=1 build):
        # https://github.com/jcmvbkbc/linux-xtensa/commit/88bd9eae01160b8518176ec8020990780152c0d6
        git remote add jcmvbkbc-xtensa https://github.com/jcmvbkbc/linux-xtensa
        git fetch --no-tags jcmvbkbc-xtensa xtensa-6.13-esp32
        git checkout 88bd9eae01160b8518176ec8020990780152c0d6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash kernel/events/