Make sure the build manager dies on an unhandled schedule exception

buildman/enums.py

@@ -10,3 +10,4 @@ class BuildServerStatus(object):
   STARTING = 'starting'
   RUNNING = 'running'
   SHUTDOWN = 'shutting_down'
+  EXCEPTION = 'exception'

buildman/server.py

@@ -180,7 +180,8 @@ class BuilderServer(object):
         scheduled = yield From(self._lifecycle_manager.schedule(build_job))
       except:
         logger.exception('Exception when scheduling job')
-        scheduled = None
+        self._current_status = BuildServerStatus.EXCEPTION
+        return
 
       if scheduled:
         status_handler = StatusHandler(self._build_logs, build_job.repo_build.uuid)
@@ -196,6 +197,7 @@ class BuilderServer(object):
   def _queue_metrics_updater(self):
     while self._current_status == BuildServerStatus.RUNNING:
       yield From(trollius.sleep(30))
+      logger.debug('Writing metrics')
       self._queue.update_metrics()
 
   @trollius.coroutine