reproduce (this is a W=1 build):
        # https://github.com/goldwynr/linux/commit/edc8da1d3d6c5a09662a7a788dc17c963f50dfab
        git remote add goldwynr https://github.com/goldwynr/linux
        git fetch --no-tags goldwynr buffered-iomap
        git checkout edc8da1d3d6c5a09662a7a788dc17c963f50dfab
        # 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