anchor.diff:  { stdenv, buildPythonPackage, fetchPypi, glibcLocales, mock, pytest, botocore,
     testfixtures, pillow, six, twisted, w3lib, lxml, queuelib, pyopenssl,
  -  service-identity, parsel, pydispatcher, cssselect, lib }:
  +  service-identity, parsel, pydispatcher, cssselect, lib, fetchpatch }:
   buildPythonPackage rec {
     version = "1.5.1";
     pname = "Scrapy";
  
positive.code:     sha256 = "5a398bf6818f87dcc817c919408a195f19ba46414ae12f259119336cfa862bb6";
    };
  
    meta = with lib; {
      description = "A fast high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages";
      homepage = https://scrapy.org/;
      license = licenses.bsd3;
      maintainers = with maintainers; [ drewkett ];
      platforms = platforms.unix;
    };
  }
  
negative.code:     six twisted w3lib lxml cssselect queuelib pyopenssl service-identity parsel pydispatcher
    ];
  
    patches = [
      # Scrapy is usually installed via pip where copying all
      # permissions makes sense. In Nix the files copied are owned by
      # root and readonly. As a consequence scrapy can't edit the
      # project templates.
      ./permissions-fix.patch
      # fix python37 issues. Remove with the next release
      (fetchpatch {
        url = https://github.com/scrapy/scrapy/commit/f4f39057cbbfa4daf66f82061e57101b88d88d05.patch;
        sha256 = "1f761qkji362i20i5bzcxz44sihvl29prm02i5l2xyhgl1hp91hv";
      })
    ];
  
    LC_ALL="en_US.UTF-8";
  
    # Ignore proxy tests because requires mitmproxy
    # Ignore test_retry_dns_error because tries to resolve an invalid dns and weirdly fails with "Reactor was unclean"
    # Ignore xml encoding test on darwin because lxml can't find encodings https://bugs.launchpad.net/lxml/+bug/707396
    checkPhase = ''
      pytest --ignore=tests/test_linkextractors_deprecated.py --ignore=tests/test_proxy_connect.py --deselect tests/test_crawl.py::CrawlTestCase::test_retry_dns_error ${lib.optionalString stdenv.isDarwin "--deselect tests/test_utils_iterators.py::LxmlXmliterTestCase::test_xmliter_encoding"}
    '';
  
    src = fetchPypi {
  