anchor.diff:    propagatedBuildInputs = runtimeDeps python3.pkgs;
   
     postInstall = ''
  -    mkdir -p "$out/share/bash-completion/completions"
  -    _PIPENV_COMPLETE=bash_source "$out/bin/pipenv" > "$out/share/bash-completion/completions/pipenv"
  -
  -    mkdir -p "$out/share/zsh/vendor-completions"
  -    _PIPENV_COMPLETE=zsh_source "$out/bin/pipenv" > "$out/share/zsh/vendor-completions/_pipenv"
  -
  -    mkdir -p "$out/share/fish/vendor_completions.d"
  -    _PIPENV_COMPLETE=fish_source "$out/bin/pipenv" > "$out/share/fish/vendor_completions.d/pipenv.fish"
  +    installShellCompletion --cmd pipenv \
  +      --bash <(_PIPENV_COMPLETE=bash_source $out/bin/pipenv) \
  +      --zsh <(_PIPENV_COMPLETE=zsh_source $out/bin/pipenv) \
  +      --fish <(_PIPENV_COMPLETE=fish_source $out/bin/pipenv)
     '';
   
     doCheck = true;
  
positive.code: { lib
  , python3
  }:
  
  with python3.pkgs;
  
negative.code: 
    LC_ALL = "en_US.UTF-8";
  
    nativeBuildInputs = [ installShellFiles ];
  
    postPatch = ''
      # pipenv invokes python in a subprocess to create a virtualenv
      # and to call setup.py.
  