anchor.diff: -{ lib, buildPythonPackage, fetchPypi, pkg-config }:
  +{ lib
  +, buildPythonPackage
  +, fetchFromGitHub
  +, poetry-core
  +, pkg-config
  +, pytestCheckHook
  +}:
   
   buildPythonPackage rec {
     pname = "pkgconfig";
     version = "1.5.5";
  +  format = "pyproject";
   
     inherit (pkg-config)
       setupHooks
  
positive.code:     description = "Interface Python with pkg-config";
      homepage = "https://github.com/matze/pkgconfig";
      license = licenses.mit;
    };
  }
  
negative.code:     suffixSalt
      targetPrefix
      baseBinName
      ;
  
    src = fetchFromGitHub {
      owner = "matze";
      repo = "pkgconfig";
      rev = "v${version}";
      sha256 = "sha256-uuLUGRNLCR3NS9g6OPCI+qG7tPWsLhI3OE5WmSI3vm8=";
    };
  
    patches = [ ./executable.patch ];
  
    postPatch = ''
      rm pkgconfig/pkgconfig.py.orig
      substituteInPlace pkgconfig/pkgconfig.py \
        --replace 'PKG_CONFIG_EXE = "pkg-config"' 'PKG_CONFIG_EXE = "${pkg-config}/bin/${pkg-config.targetPrefix}pkg-config"'
  
      # those pc files are missing and pkg-config validates that they exist
      substituteInPlace data/fake-openssl.pc \
        --replace "Requires: libssl libcrypto" ""
    '';
  
    nativeBuildInputs = [ poetry-core ];
  
    propagatedNativeBuildInputs = [ pkg-config ];
  
    checkInputs = [ pytestCheckHook ];
  
    pythonImportsCheck = [ "pkgconfig" ];
  
  