anchor.diff:  
   buildPythonPackage rec {
     pname = "SQLAlchemy";
  -  version = "1.2.12";
  +  version = "1.2.13";
   
     src = fetchPypi {
       inherit pname version;
  -    sha256 = "c5951d9ef1d5404ed04bae5a16b60a0779087378928f997a294d1229c6ca4d3e";
  +    sha256 = "84412de3794acee05630e7788f25e80e81f78eb4837e7b71d0499129f660486a";
     };
  +
  +  patches = [
  +    # fix for failing doc tests
  +    # https://bitbucket.org/zzzeek/sqlalchemy/issues/4370/sqlite-325x-docs-tutorialrst-doctests-fail
  +    (fetchpatch {
  +      name = "doc-test-fixes.patch";
  +      url = https://bitbucket.org/zzzeek/sqlalchemy/commits/63279a69e2b9277df5e97ace161fa3a1bb4f29cd/raw;
  +      sha256 = "1x25aj5hqmgjdak4hllya0rf0srr937k1hwaxb24i9ban607hjri";
  +    })
  +  ];
   
     checkInputs = [
       pytest
  
positive.code:     description = "A Python SQL toolkit and Object Relational Mapper";
      license = licenses.mit;
    };
  }
negative.code: { lib
  , fetchPypi
  , fetchpatch
  , buildPythonPackage
  , pytest
  , mock
  