Revert "Separate from operating system."

This reverts commit 84b1322c.

I want to wrong way.

component/ncurses/buildout.cfg

@@ -17,9 +17,5 @@ make-targets =
   install && (for i in curses unctrl eti form menu panel term; do ln -sf ncurses/$i.h ${buildout:parts-directory}/${:_buildout_section_name_}/include/$i.h; done) && ./configure ${:configure-options} --enable-widec && make install
 environment =
   LDFLAGS =-Wl,--as-needed
-  CFLAGS =
-  CPPFLAGS =
-  LDFLAGS =
-  LD_LIBRARY_PATH =
 make-options =
   -j1