introduce recipe_exception in result.proto

recipes.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """Tool to interact with recipe repositories.
 
 This tool operates on the nearest ancestor directory containing an
 infra/config/recipes.cfg.
 """
@@ skipping 140 matching lines @@
           result, including_default_value_fields=True))
 
   if result.json_result:
     with stream_engine.make_step_stream('recipe result') as s:
       with s.new_log_stream('result') as l:
         l.write_split(result.json_result)
 
   if result.HasField('failure'):
     f = result.failure
     if f.HasField('exception'):
-      with stream_engine.make_step_stream('Uncaught Exception') as s:
+      with stream_engine.make_step_stream(
+          'Uncaught Exception in recipe engine') as s:
         s.add_step_text(f.human_reason)
         with s.new_log_stream('exception') as l:
           for line in f.exception.traceback:
+            l.write_line(line)
+    elif f.HasField('recipe_exception'):
+      with stream_engine.make_step_stream('Uncaught Exception in recipe') as s:
+        s.add_step_text(f.human_reason)
+        with s.new_log_stream('exception') as l:
+          for line in f.exception.traceback:
             l.write_line(line)
     # TODO(martiniss): Remove this code once calling code handles these states
     elif f.HasField('timeout'):
       with stream_engine.make_step_stream('Step Timed Out') as s:
         with s.new_log_stream('timeout_s') as l:
           l.write_line(f.timeout.timeout_s)
     elif f.HasField('step_data'):
       with stream_engine.make_step_stream('Invalid Step Data Access') as s:
         with s.new_log_stream('step') as l:
           l.write_line(f.step_data.step)
@@ skipping 587 matching lines @@
 
   if not isinstance(ret, int):
     if ret is None:
       ret = 0
     else:
       print >> sys.stderr, ret
       ret = 1
   sys.stdout.flush()
   sys.stderr.flush()
   os._exit(ret)