reproduce (this is a W=1 build):
        git checkout 6f85aad74a70d17919a64ecd93037aa51c08698d
        b4 shazam https://lore.kernel.org/r/20251117-rneri-wakeup-mailbox-v7-8-4a8b82ab7c2c@linux.intel.com

        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=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/hyperv/