anchor.diff:      libwebp
       gl2ps
     ]
  -  ++ (stdenv.lib.optionals enableQt [
  +  ++ stdenv.lib.optionals enableQt [
       qtbase
       qtsvg
       qscintilla
  -  ])
  -  ++ (stdenv.lib.optional (ghostscript != null) ghostscript)
  -  ++ (stdenv.lib.optional (hdf5 != null) hdf5)
  -  ++ (stdenv.lib.optional (glpk != null) glpk)
  -  ++ (stdenv.lib.optional (suitesparse != null) suitesparse)
  -  ++ (stdenv.lib.optional (enableJava) jdk)
  -  ++ (stdenv.lib.optional (sundials_2 != null) sundials_2)
  -  ++ (stdenv.lib.optional (gnuplot != null) gnuplot)
  -  ++ (stdenv.lib.optional (python != null) python)
  -  ++ (stdenv.lib.optionals (!stdenv.isDarwin) [ libGL libGLU libX11 ])
  -  ++ (stdenv.lib.optionals (stdenv.isDarwin) [ libiconv
  -                                               darwin.apple_sdk.frameworks.Accelerate
  -                                               darwin.apple_sdk.frameworks.Cocoa ])
  +  ]
  +  ++ stdenv.lib.optionals (ghostscript != null) [ ghostscript ]
  +  ++ stdenv.lib.optionals (hdf5 != null) [ hdf5 ]
  +  ++ stdenv.lib.optionals (glpk != null) [ glpk ]
  +  ++ stdenv.lib.optionals (suitesparse != null) [ suitesparse ]
  +  ++ stdenv.lib.optionals (enableJava) [ jdk ]
  +  ++ stdenv.lib.optionals (sundials_2 != null) [ sundials_2 ]
  +  ++ stdenv.lib.optionals (gnuplot != null) [ gnuplot ]
  +  ++ stdenv.lib.optionals (python != null) [ python ]
  +  ++ stdenv.lib.optionals (!stdenv.isDarwin) [ libGL libGLU libX11 ]
  +  ++ stdenv.lib.optionals stdenv.isDarwin [
  +    libiconv
  +    darwin.apple_sdk.frameworks.Accelerate
  +    darwin.apple_sdk.frameworks.Cocoa
  +  ]
     ;
     nativeBuildInputs = [
       pkgconfig
  
positive.code:     "--with-lapack=lapack"
      (if blas.isILP64 then "--enable-64" else "--disable-64")
    ]
      ++ (if stdenv.isDarwin then [ "--enable-link-all-dependencies" ] else [ ])
      ++ stdenv.lib.optionals enableReadline [ "--enable-readline" ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ "--with-x=no" ]
      ++ stdenv.lib.optionals enableQt [ "--with-qt=5" ]
  
negative.code:     fftwSinglePrec
      texinfo
    ]
    ++ stdenv.lib.optionals (sundials_2 != null) [ sundials_2 ]
    ++ stdenv.lib.optionals enableJIT [ llvm ]
    ++ stdenv.lib.optionals enableQt [
      qtscript
      qttools
    ]
    ;
  
    doCheck = !stdenv.isDarwin;
  