reproduce (this is a W=1 build):
        git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
        git fetch tip irq/core
        git checkout tip/irq/core
        b4 shazam https://lore.kernel.org/r/20251217112128.1401896-2-lrizzo@google.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 kernel/