reproduce (this is a W=1 build):
        git remote add pci https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git
        git fetch pci next
        git checkout pci/next
        b4 shazam https://lore.kernel.org/r/20260312224713.1305228-1-bhelgaas@google.com
        # apt-get install llvm-dev

        # save the config file
        make W=1 ARCH=x86_64 olddefconfig
        make W=1 ARCH=x86_64 
        make W=1 headers_install
        make W=1 -C tools/testing/selftests