anchor.diff:      coqpit
       flask
       fsspec
  +    gdown
       gruut
  -    gdown
       inflect
       jieba
       librosa
  
positive.code:     pandas
      pypinyin
      pysbd
      pytorch
      pyworld
      scipy
      soundfile
      tensorboardx
      tensorflow
      tqdm
      umap-learn
      unidic-lite
    ];
  
    postInstall = ''
  
negative.code: 
  python3.pkgs.buildPythonApplication rec {
    pname = "tts";
    version = "0.5.0";
    format = "setuptools";
  
    src = fetchFromGitHub {
      owner = "coqui-ai";
      repo = "TTS";
      rev = "v${version}";
      sha256 = "sha256-9fNYNhHS9wqrk2bZnrkkGU1OaDu/16RA8fz+Zj9xsyQ=";
    };
  
    postPatch = let
      relaxedConstraints = [
        "gruut"
        "librosa"
        "mecab-python3"
        "numba"
        "numpy"
        "umap-learn"
        "torch"
      ];
    in ''
      sed -r -i \
        ${lib.concatStringsSep "\n" (map (package:
          ''-e 's/${package}.*[<>=]+.*/${package}/g' \''
        ) relaxedConstraints)}
      requirements.txt
    '';
  
    nativeBuildInputs = with python3.pkgs; [
  