Allow base path overrides when running a recipe.

recipe_engine/loader.py

 # Copyright 2013-2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import collections
 import contextlib
 import imp
 import inspect
 import os
 import sys
@@ skipping 333 matching lines @@
 def _load_recipe_module_module(path, universe_view):
   modname = os.path.splitext(os.path.basename(path))[0]
   fullname = '%s.%s' % (RECIPE_MODULE_PREFIX, modname)
   mod = _find_and_load_module(fullname, modname, path)
 
   # This actually loads the dependencies.
   mod.LOADED_DEPS = universe_view.deps_from_spec(getattr(mod, 'DEPS', []))
 
   # Prevent any modules that mess with sys.path from leaking.
   with _preserve_path():
-    # TODO(luqui): Remove this hack once configs are cleaned.
     sys.modules['%s.DEPS' % fullname] = mod.LOADED_DEPS
     _recursive_import(path, RECIPE_MODULE_PREFIX)
     _patchup_module(modname, mod, universe_view)
 
   return mod
 
 
 def _recursive_import(path, prefix):
   modname = os.path.splitext(os.path.basename(path))[0]
   fullname = '%s.%s' % (prefix, modname)
@@ skipping 207 matching lines @@
     modapi = (getattr(mod, 'TEST_API', None) or RecipeTestApi)(module=mod)
     for k,v in deps.iteritems():
       setattr(modapi.m, k, v)
     return modapi
 
   mapper = DependencyMapper(instantiator)
   api = RecipeTestApi(module=None)
   for k,v in toplevel_deps.iteritems():
     setattr(api, k, mapper.instantiate(v))
   return api