Formally define step config, pass to stream.

recipe_modules/step/api.py

 # Copyright 2013 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.
 
 import contextlib
+import datetime
 
 from recipe_engine import recipe_api
 
 
 # Inherit from RecipeApiPlain because the only thing which is a step is
 # run_from_dict()
 class StepApi(recipe_api.RecipeApiPlain):
   def __init__(self, **kwargs):
     super(StepApi, self).__init__(**kwargs)
     self._step_names = {}
@@ skipping 140 matching lines @@
     if 'cwd' not in kwargs:
       kwargs['cwd'] = compositor.get('cwd')
     kwargs['env'] = compositor.get_with_context('env', kwargs.get('env', {}))
     kwargs['infra_step'] = compositor.get_with_context(
         'infra_step', bool(infra_step))
     kwargs['step_nest_level'] = compositor.get_with_context('nest_level', 0)
     kwargs['name'] = full_name
 
     schema = self.make_config()
     schema.set_val(kwargs)
-    return self.run_from_dict(self._engine.create_step(schema))
+    return self.run_from_dict(schema.as_jsonish())
 
   # TODO(martiniss) delete, and make generator_script use **kwargs on step()
   @recipe_api.composite_step
   def run_from_dict(self, dct):
     return self._engine.run_step(dct)