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:     six twisted w3lib lxml cssselect queuelib pyopenssl service-identity parsel pydispatcher
    ];
  
    # 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.
    patches = [ ./permissions-fix.patch ];
  
    LC_ALL="en_US.UTF-8";
  
    checkPhase = ''
      py.test --ignore=tests/test_linkextractors_deprecated.py --ignore=tests/test_proxy_connect.py ${lib.optionalString stdenv.isDarwin "--ignore=tests/test_utils_iterators.py"}
      # The ignored tests require mitmproxy, which depends on protobuf, but it's disabled on Python3
      # Ignore iteration test, because lxml can't find encodings on darwin https://bugs.launchpad.net/lxml/+bug/707396
    '';
  
    src = fetchPypi {
  
negative.code:     sha256 = "5a398bf6818f87dcc817c919408a195f19ba46414ae12f259119336cfa862bb6";
    };
  
    postInstall = ''
      install -m 644 -D extras/scrapy.1 $out/share/man/man1/scrapy.1
      install -m 644 -D extras/scrapy_bash_completion $out/share/bash-completion/completions/scrapy
      install -m 644 -D extras/scrapy_zsh_completion $out/share/zsh/site-functions/_scrapy
    '';
  
    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 marsam ];
      platforms = platforms.unix;
    };
  }
  