anchor.diff:      sha256 = sha256Hash;
     };
   
  -  propagatedBuildInputs = [ yarl aiohttp aiohttp-cors multidict_3_1_3 ]
  +  propagatedBuildInputs = [ aiohttp-cors ]
       ++ (with pythonPackages; [
  +      yarl aiohttp multidict
         jinja2 psutil zipstream raven jsonschema typing
         prompt_toolkit
       ]);
  -
  -  postPatch = ''
  -    sed -i 's/yarl>=0.11,<0.12/yarl/g' requirements.txt
  -  '';
   
     # Requires network access
     doCheck = false;
  
positive.code: 
  let
    pythonPackages = python3Packages;
    # TODO: Not sure if all these overwrites are really required...
    # Upstream seems to have some reasons (bugs, incompatibilities) though.
    multidict_3_1_3 =
      (stdenv.lib.overrideDerivation pythonPackages.multidict (oldAttrs:
        rec {
          pname = "multidict";
          version = "3.1.3";
          name = "${pname}-${version}";
          src = pythonPackages.fetchPypi {
            inherit pname version;
            sha256 = "04kdxh19m41c6vbshwk8jfbidsfsqn7mn0abvx09nyg78sh80pw7";
          };
          doInstallCheck = false;
        }));
    yarl = (stdenv.lib.overrideDerivation pythonPackages.yarl
      (oldAttrs:
        { propagatedBuildInputs = [ multidict_3_1_3 pythonPackages.idna ]; }));
    aiohttp = (stdenv.lib.overrideDerivation pythonPackages.aiohttp
      (oldAttrs:
        rec {
          propagatedBuildInputs = [ yarl multidict_3_1_3 ]
            ++ (with pythonPackages; [ async-timeout chardet ]);
        }));
    aiohttp-cors = (stdenv.lib.overrideDerivation pythonPackages.aiohttp-cors
      (oldAttrs:
        rec {
  
negative.code:           inherit pname version;
            sha256 = "11b51mhr7wjfiikvj3nc5s8c7miin2zdhl3yrzcga4mbpkj892in";
          };
        }));
  in pythonPackages.buildPythonPackage rec {
    name = "${pname}-${version}";
  