anchor.diff: -{ buildPythonPackage, lib, fetchFromGitHub, isPy27, nixosTests, fetchpatch
  +{ buildPythonPackage, lib, fetchFromGitHub, isPy27, nixosTests, fetchpatch, fetchPypi
   , alembic
   , aniso8601
   , Babel
  
positive.code:     flask-restful
      flask_script
      flask_sqlalchemy
      flask_wtf
      idna
      itsdangerous
      jinja2
  
negative.code:     sqlalchemy
      sqlalchemy-continuum
      werkzeug
      pinned_wtforms
      psycopg2
      debts
    ];
  