reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/commit/?id=7d9d9c209c495466776a212b70b5bb4c9fc58188
        git remote add conor https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git
        git fetch --no-tags conor pinctrl
        git checkout 7d9d9c209c495466776a212b70b5bb4c9fc58188

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/pinctrl/