anchor.diff:    # fix over-restrictive version bounds
     postPatch = ''
       substituteInPlace requirements/base.txt \
  -      --replace "boto3~=1.13.0, >=1.13.0" "boto3~=1.14.3" \
  +      --replace "boto3~=1.14.0, >=1.14.23" "boto3~=1.14" \
  +      --replace "docker~=4.2.0" "docker~=4.3.1" \
  +      --replace "jmespath~=0.9.5" "jmespath~=0.10.0" \
  +      --replace "python-dateutil~=2.6, <2.8.1" "python-dateutil~=2.6" \
  +      --replace "requests==2.23.0" "requests~=2.24" \
         --replace "serverlessrepo==0.1.9" "serverlessrepo~=0.1.9" \
  -      --replace "python-dateutil~=2.6, <2.8.1" "python-dateutil~=2.6" \
  -      --replace "jmespath~=0.9.5" "jmespath~=0.10.0" \
  -      --replace "tomlkit==0.5.8" "tomlkit~=0.7.0" \
  -      --replace "requests==2.23.0" "requests~=2.24"
  +      --replace "tomlkit==0.5.8" "tomlkit~=0.7.0"
     '';
   
     meta = with lib; {
  
positive.code: let
    py = python.override {
      packageOverrides = self: super: {
        aws-sam-translator = super.aws-sam-translator.overridePythonAttrs (oldAttrs: rec {
          version = "1.25.0";
          src = oldAttrs.src.override {
            inherit version;
            sha256 = "08756yl5lpqgrpr80f2b6bdcgygr37l6q1yygklcg9hz4yfpccav";
          };
        });
  
        flask = super.flask.overridePythonAttrs (oldAttrs: rec {
          version = "1.0.2";
          src = oldAttrs.src.override {
  
negative.code: 
  buildPythonApplication rec {
    pname = "aws-sam-cli";
    version = "1.6.2";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "0scnymhhiiqrs2j0jaypxgq2wg1qf1w8f55qfay0b3nf51y6mh8y";
    };
  
    # Tests are not included in the PyPI package
  