Why MAKEFLAGS is set to `w' in sub directory?

[Masato Asou]

Hello,

Why MAKEFLAGS is set to `w' in sub directory?

When I invoke make command in sub directory. Then MAKEFLAGS is not set.

    $ cd sub
    $ make
    !!! Debug: MAKEFLAGS =

However, I invoke make command in parent directory, then MAKEFLAGS is set
to `w' in sub directory.

    $ cd ..
    $ make
    !!! Debug: MAKEFLAGS =
    make -C sub
    make[1]: Entering directory `/home/asou/tmp/sample/sub'
    !!! Debug: MAKEFLAGS = w
    make[1]: Leaving directory `/home/asou/tmp/sample/sub'

My Makefiles are below.

    $ cat Makefile
    all:
            @echo "!!! Debug: MAKEFLAGS = $(MAKEFLAGS)"
            make -C sub
    $ cat sub/Makefile
    all:
            @echo "!!! Debug: MAKEFLAGS = $(MAKEFLAGS)"

I am using Centos 7.2 on VMware FUSION.

    $ cat /etc/redhat-release
    CentOS Linux release 7.2.1511 (Core)

I am using GNU Make 3.82.

    $ which make
    /usr/bin/make
    address@hidden:~/tmp/sample 17:52:11
    $ make -v
    GNU Make 3.82
    Built for x86_64-redhat-linux-gnu
    Copyright (C) 2010  Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.

My environment valiables are below:

    $ printenv
    XDG_SESSION_ID=1
    HOSTNAME=vmcentos
    SELINUX_ROLE_REQUESTED=
    TERM=xterm-256color
    SHELL=/bin/bash
    HISTSIZE=1000
    SSH_CLIENT=192.168.0.1 56676 22
    SELINUX_USE_CURRENT_RANGE=
    OLDPWD=/home/asou/tmp/sample/sub
    SSH_TTY=/dev/pts/0
    USER=asou
    LD_LIBRARY_PATH=/home/asou/local/vtk-6.3.0/lib:/usr/lib64/openmpi/lib
    LS_COLORS=rs=0:di=38;5;27:ln=38;5;51:mh=44;38;5;15:pi=40;38
    <snip LS_SOLORS>
    SSH_AUTH_SOCK=/tmp/ssh-o3pcsnE6CU/agent.3176
    MAIL=/var/spool/mail/asou
    
PATH=/home/asou/local/emacs-23.3/bin:/home/asou/local/swig-3.0.8/bin:/usr/lib64/openmpi/bin:/home/asou/local/vtk-6.3.0/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/asou/.local/bin:/home/asou/bin
    PWD=/home/asou/tmp/sample
    LANG=
    MODULEPATH=/usr/share/Modules/modulefiles:/etc/modulefiles
    LOADEDMODULES=
    ELAI_INC=/home/asou/local/elai-0.6.2/include
    SELINUX_LEVEL_REQUESTED=
    HISTCONTROL=ignoredups
    SHLVL=1
    HOME=/home/asou
    ELAI_LIB=/home/asou/local/elai-0.6.2/lib
    PYTHONPATH=/home/asou/local/vtk-6.3.0/lib/python./site-packages
    LOGNAME=asou
    SSH_CONNECTION=192.168.231.1 56676 192.168.231.128 22
    MODULESHOME=/usr/share/Modules
    LESSOPEN=||/usr/bin/lesspipe.sh %s
    XDG_RUNTIME_DIR=/run/user/1000
    DISPLAY=localhost:10.0
    BASH_FUNC_module()=() {  eval `/usr/bin/modulecmd bash $*`
    }
    _=/usr/bin/printenv

Thanks.
--
ASOU Masato