anchor.diff:  , givaro
   , pkgconfig
   , openblas
  -, liblapack
   , fflas-ffpack
   , gmpxx
   , optimize ? false # impure
  
positive.code: 
    buildInputs = [
      givaro
      (liblapack.override {shared = true;})
      openblas
      gmpxx
      fflas-ffpack
  
negative.code: 
    configureFlags = [
      "--with-blas-libs=-lopenblas"
      "--disable-optimization"
    ] ++ stdenv.lib.optionals (!optimize) [
      # disable SIMD instructions (which are enabled *when available* by default)
  