reproduce (this is a W=1 build):
        git remote add herbert-crypto-2.6 https://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6.git
        git fetch herbert-crypto-2.6 master
        git checkout herbert-crypto-2.6/master
        b4 shazam https://lore.kernel.org/r/20250901164212.460229-4-ethan.w.s.graham@gmail.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um olddefconfig
        make W=1 O=build_dir ARCH=um SHELL=/bin/bash