reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/harry/linux.git/commit/?id=dd7b7336ad2c3f9589f28e095aed50717e65f0d5
        git remote add harry https://git.kernel.org/pub/scm/linux/kernel/git/harry/linux.git
        git fetch --no-tags harry kvfree-rcu-improvements-rfc-v2r1-wip
        git checkout dd7b7336ad2c3f9589f28e095aed50717e65f0d5

        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=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=mips olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash