anchor.diff:      cmake
       m17n_lib
       m17n_db
  +    expat
     ]
     ++ optional withAnthy anthy
     ++ optional withGtk2 gtk2
  
positive.code: { stdenv, fetchurl, intltool, pkgconfig, cmake
  , ncurses, m17n_lib, m17n_db
  , withAnthy ? true, anthy ? null
  , withGtk ? true
  , withGtk2 ? withGtk, gtk2 ? null
  
negative.code:     "--with-skk"
      "--with-x"
      "--with-xft"
      "--with-expat=${expat.dev}"
    ]
    ++ optional withAnthy "--with-anthy-utf8"
    ++ optional withGtk2 "--with-gtk2"
  