anchor.diff:      installPhase = installer crossB2Args;
       postFixup = fixup;
     };
  +
  +  meta = {
  +    homepage = "http://boost.org/";
  +    description = "Collection of C++ libraries";
  +    license = stdenv.lib.licenses.boost;
  +    platforms = platforms.unix;
  +    maintainers = with maintainers; [ simons wkennington ];
  +  };
   }
  
positive.code: 
    inherit src patches;
  
    meta = {
      homepage = "http://boost.org/";
      description = "Collection of C++ libraries";
      license = stdenv.lib.licenses.boost;
  
      platforms = platforms.unix;
      maintainers = with maintainers; [ simons wkennington ];
    };
  
    preConfigure = ''
      NIX_LDFLAGS="$(echo $NIX_LDFLAGS | sed "s,$out,$lib,g")"
      if test -f tools/build/src/tools/clang-darwin.jam ; then
  
negative.code:     EOF
    '';
  
    enableParallelBuilding = true;
  
    buildInputs = [ icu expat zlib bzip2 python2 ];
  
    configureScript = "./bootstrap.sh";
    configureFlags = commonConfigureFlags ++ [
      "--with-icu=${icu}"
      "--with-python=${python2.interpreter}"
    ] ++ optional (toolset != null) "--with-toolset=${toolset}";
  
    buildPhase = builder nativeB2Args;
  