anchor.diff:    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 = ''
  
positive.code: { lib, buildPythonApplication, fetchFromGitHub, bash, cmake, flex
  , libclang, llvm, unifdef
  , chardet, pebble, psutil, pytestCheckHook, pytest-flake8
  }:
  
  buildPythonApplication rec {
  
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;
  