reproduce (this is a W=1 build):
        git checkout c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9
        b4 shazam https://lore.kernel.org/r/20250923-bootcache-v1-2-4f86fdc38b4e@thegoodpenguin.co.uk
        # 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 lib/raid6/