anchor.diff:      "-DIGRAPH_USE_INTERNAL_GLPK=OFF"
       "-DIGRAPH_USE_INTERNAL_CXSPARSE=OFF"
       "-DIGRAPH_USE_INTERNAL_GMP=OFF"
  +    "-DIGRAPH_USE_INTERNAL_PLFIT=OFF"
       "-DIGRAPH_GLPK_SUPPORT=ON"
       "-DIGRAPH_GRAPHML_SUPPORT=ON"
  +    "-DIGRAPH_OPENMP_SUPPORT=ON"
       "-DIGRAPH_ENABLE_LTO=AUTO"
       "-DIGRAPH_ENABLE_TLS=ON"
       "-DBUILD_SHARED_LIBS=ON"
  
positive.code:     gmp
      lapack
      libxml2
      suitesparse
    ];
  
    cmakeFlags = [
  
negative.code:     sha256 = "sha256-SL9PcT18vFvykCv4VRXxXtlcDAcybmwEImnnKXMciFQ=";
    };
  
    postPatch = ''
      echo "${version}" > IGRAPH_VERSION
    '' + lib.optionalString stdenv.isAarch64 ''
  