reproduce (this is a W=1 build):
        # https://github.com/dsahern/linux/commit/ae20d62bc3e42f44ed7113d792ceb545036ca61d
        git remote add dsahern https://github.com/dsahern/linux
        git fetch --no-tags dsahern netdevsim-speed
        git checkout ae20d62bc3e42f44ed7113d792ceb545036ca61d

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sh olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sh SHELL=/bin/bash drivers/net/netdevsim/