anchor.diff:  , fetchFromGitHub
   , bash
   , cmake
  +, colordiff
   , flex
   , libclang
   , llvm
  
positive.code:     substituteInPlace cvise.py \
        --replace "#!/bin/bash" "#!${bash}/bin/bash"
  
      substituteInPlace setup.cfg \
        --replace "--flake8" ""
    '';
  
    nativeBuildInputs = [
  
negative.code:     unifdef
    ];
  
    disabledTests = [
      # Needs gcc, fails when run noninteractively (without tty).
      "test_simple_reduction"
  