anchor.diff: -{ stdenv, fetchurl, makeWrapper, pkgconfig
  +{ stdenv, darwin, fetchurl, makeWrapper, pkgconfig
   , harfbuzz, icu, lpeg, luaexpat, luazlib, luafilesystem
   , fontconfig, lua, libiconv
   }:
  
positive.code:   };
  
    nativeBuildInputs = [pkgconfig makeWrapper];
    buildInputs = [ harfbuzz icu lua lpeg luaexpat luazlib luafilesystem fontconfig libiconv ];
  
    LUA_PATH = luaPath;
    LUA_CPATH = luaCPath;
  
negative.code:       technologies and borrowing some ideas from graphical systems
        such as InDesign.
      '';
      homepage = http://www.sile-typesetter.org;
      platforms = platforms.unix;
      license = licenses.mit;
    };
  }
  