reproduce (this is a W=1 build):
        git checkout e04c78d86a9699d136910cfc0bdcf01087e3267e
        b4 shazam https://lore.kernel.org/r/10-v2-4a9b9c983431+10e2-pcie_switch_groups_jgg@nvidia.com
        # 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