[context] Split "env" values and prefixes.

recipe_modules/generator_script/api.py

 # Copyright 2017 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 from recipe_engine import recipe_api
 
 class GeneratorScriptApi(recipe_api.RecipeApi):
   def __call__(self, path_to_script, *args, **kwargs):
     """Run a script and generate the steps emitted by that script.
 
@@ skipping 39 matching lines @@
             page. Note that these are write-only: The only way to read them is
             via the status page. There is intentionally no mechanism to read
             them back from inside of the recipes.
 
     kwargs:
       env - The environment for the generated steps.
     """
     f = '--output-json'
     step_name = 'gen step(%s)' % self.m.path.basename(path_to_script)
 
+    kwargs.setdefault('pathsep', self.m.path.pathsep)
     step_test_data = kwargs.pop('step_test_data', None)
     with self.m.context(cwd=self.m.path['checkout']):
       if str(path_to_script).endswith('.py'):
         step_result = self.m.python(
           step_name,
           path_to_script, list(args) + [f, self.m.json.output()],
           step_test_data=step_test_data)
       else:
         step_result = self.m.step(
           step_name,
@@ skipping 38 matching lines @@
               p.logs.update(j.get('logs', {}))
               p.links.update(j.get('links', {}))
               p.step_summary_text = j.get('step_summary_text', '')
               p.step_text = j.get('step_text', '')
               p.properties.update(j.get('properties', {}))
 
     if failed_steps:
       raise self.m.step.StepFailure(
         "the following steps in %s failed: %s" %
         (step_name, failed_steps))