anchor.diff:  { lib, buildPythonApplication, fetchFromGitHub, bash, cmake, flex
   , libclang, llvm, unifdef
  -, chardet, pebble, psutil, pytestCheckHook, pytest-flake8
  +, chardet, pebble, psutil
   }:
   
   buildPythonApplication rec {
  
positive.code:   nativeBuildInputs = [ cmake flex llvm.dev ];
    buildInputs = [ bash libclang llvm llvm.dev unifdef ];
    propagatedBuildInputs = [ chardet pebble psutil ];
    checkInputs = [ pytestCheckHook pytest-flake8 unifdef ];
  
    # 'cvise --command=...' generates a script with hardcoded shebang.
    postPatch = ''
  
negative.code:       --replace "#!/bin/bash" "#!${bash}/bin/bash"
    '';
  
    # pytest-flake8 is broken in nixpkgs: https://github.com/tholo/pytest-flake8/issues/87
    doCheck = false;
    dontUsePipInstall = true;
    dontUseSetuptoolsBuild = true;
    dontUseSetuptoolsCheck = true;
  