anchor.diff:  
     env-canada = callPackage ../development/python-modules/env-canada { };
   
  -  environmental-override = callPackage ../development/python-modules/environmental-override {};
  +  environmental-override = callPackage ../development/python-modules/environmental-override { };
   
     envisage = callPackage ../development/python-modules/envisage { };
   
  
positive.code: 
    class-registry = callPackage ../development/python-modules/class-registry { };
  
    claripy =  callPackage ../development/python-modules/claripy { };
  
    cld2-cffi = callPackage ../development/python-modules/cld2-cffi { };
  
  
negative.code:   # See build-setupcfg/default.nix for documentation.
    buildSetupcfg = import ../build-support/build-setupcfg self;
  
    fetchPypi = callPackage ../development/interpreters/python/fetchpypi.nix { };
  
    # Check whether a derivation provides a Python module.
    hasPythonModule = drv: drv?pythonModule && drv.pythonModule == python;
  