reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/commit/?id=70cf1c0aef205f9384095f2536c61b945d320ef6
        git remote add mszeredi-fuse https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git
        git fetch --no-tags mszeredi-fuse extent-map-v4
        git checkout 70cf1c0aef205f9384095f2536c61b945d320ef6

        # 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