reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git/commit/?id=223bfb57631b10036e55579ecb5718123fa41c8c
        git remote add jack-fs https://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git
        git fetch --no-tags jack-fs for_next
        git checkout 223bfb57631b10036e55579ecb5718123fa41c8c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash fs/quota/