anchor.diff:    ++ 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 (suitesparse != null) [ suitesparse' ]
     ++ stdenv.lib.optionals (enableJava) [ jdk ]
     ++ stdenv.lib.optionals (sundials_2 != null) [ sundials_2 ]
     ++ stdenv.lib.optionals (gnuplot != null) [ gnuplot ]
  
positive.code: , fftwSinglePrec
  , zlib
  , curl
  , qrupdate
  , blas, lapack
  , arpack
  , libwebp
  , gl2ps
  , ghostscript ? null
  , hdf5 ? null
  , glpk ? null
  , suitesparse ? null
  , gnuplot ? null
  # - Include support for GNU readline:
  , enableReadline ? true
  
negative.code:   enableParallelBuilding = true;
  
    # See https://savannah.gnu.org/bugs/?50339
    F77_INTEGER_8_FLAG = if use64BitIdx then "-fdefault-integer-8" else "";
  
    configureFlags = [
      "--with-blas=blas"
      "--with-lapack=lapack"
      (if use64BitIdx then "--enable-64" else "--disable-64")
    ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ "--enable-link-all-dependencies" ]
      ++ stdenv.lib.optionals enableReadline [ "--enable-readline" ]
  