reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git/commit/?id=adee8c9238d58cd7c6e5dcd4dca255ef72da4cac
        git remote add jpoimboe https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git
        git fetch --no-tags jpoimboe klp-build
        git checkout adee8c9238d58cd7c6e5dcd4dca255ef72da4cac
        # 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 crypto/ drivers/bus/mhi/host/ drivers/hwspinlock/ drivers/scsi/ drivers/tty/hvc/ drivers/virtio/ lib/ net/dsa/ net/mac80211/ net/sunrpc/ net/tipc/