anchor.diff:  
     buildInputs = [ gfortran readline ncurses perl flex texinfo qhull libX11
       graphicsmagick pcre pkgconfig mesa fltk zlib curl openblas libsndfile
  -    fftw fftwSinglePrec qrupdate ]
  +    fftw fftwSinglePrec qrupdate arpack libwebp ]
       ++ (stdenv.lib.optional (qt != null) qt)
       ++ (stdenv.lib.optional (qscintilla != null) qscintilla)
       ++ (stdenv.lib.optional (ghostscript != null) ghostscript)
  
positive.code:     ++ (stdenv.lib.optional (jdk != null) jdk)
      ++ (stdenv.lib.optional (gnuplot != null) gnuplot)
      ++ (stdenv.lib.optional (python != null) python)
      ;
  
    doCheck = true;
  
    enableParallelBuilding = true;
  
  
negative.code: { stdenv, fetchurl, gfortran, readline, ncurses, perl, flex, texinfo, qhull
  , libsndfile, libX11, graphicsmagick, pcre, pkgconfig, mesa, fltk
  , fftw, fftwSinglePrec, zlib, curl, qrupdate, openblas, arpack, libwebp
  , qt ? null, qscintilla ? null, ghostscript ? null, llvm ? null, hdf5 ? null,glpk ? null
  , suitesparse ? null, gnuplot ? null, jdk ? null, python ? null
  }:
  