fix: address PR review comments — tracing override, executor init order, stdin guard, unused import

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/crewai/src/crewai/events/event_bus.py

@@ -417,11 +417,6 @@ class CrewAIEventsBus:
             ...     await asyncio.wrap_future(future)  # In async test
             ...     # or future.result(timeout=5.0) in sync code
         """
-        # Lazily initialize executor and event loop on first emit
-        self._ensure_executor_initialized()
-        # Track that we have pending events for flush optimization
-        self._has_pending_events = True
-
         event.previous_event_id = get_last_event_id()
         event.triggered_by_event_id = get_triggering_event_id()
         event.emission_sequence = get_next_emission_sequence()
@@ -457,6 +452,15 @@ class CrewAIEventsBus:
             sync_handlers = self._sync_handlers.get(event_type, frozenset())
             async_handlers = self._async_handlers.get(event_type, frozenset())
 
+        # Skip executor initialization if no handlers exist for this event
+        if not sync_handlers and not async_handlers:
+            return None
+
+        # Lazily initialize executor and event loop only when handlers exist
+        self._ensure_executor_initialized()
+        # Track that we have pending events for flush optimization
+        self._has_pending_events = True
+
         if has_dependencies:
             return self._track_future(
                 asyncio.run_coroutine_threadsafe(

lib/crewai/src/crewai/events/listeners/tracing/trace_listener.py

@@ -17,7 +17,7 @@ from crewai.events.listeners.tracing.first_time_trace_handler import (
 from crewai.events.listeners.tracing.trace_batch_manager import TraceBatchManager
 from crewai.events.listeners.tracing.types import TraceEvent
 from crewai.events.listeners.tracing.utils import (
-    is_tracing_enabled,
+    is_tracing_enabled_in_context,
     safe_serialize_to_dict,
     should_auto_collect_first_time_traces,
     should_enable_tracing,
@@ -203,7 +203,8 @@ class TraceCollectionListener(BaseEventListener):
 
         # Skip registration entirely if tracing is disabled and not first-time user
         # This avoids overhead of 50+ handler registrations when tracing won't be used
-        if not should_enable_tracing() and not should_auto_collect_first_time_traces():
+        # Also check is_tracing_enabled_in_context() so per-run overrides (Crew(tracing=True)) still work
+        if not should_enable_tracing() and not is_tracing_enabled_in_context() and not should_auto_collect_first_time_traces():
             self._listeners_setup = True
             return
 

lib/crewai/src/crewai/events/listeners/tracing/utils.py

@@ -489,7 +489,16 @@ def _is_interactive_terminal() -> bool:
     """
     import sys
 
-    return sys.stdin.isatty()
+    try:
+        stdin = getattr(sys, 'stdin', None)
+        if stdin is None:
+            return False
+        isatty = getattr(stdin, 'isatty', None)
+        if not callable(isatty):
+            return False
+        return bool(isatty())
+    except Exception:
+        return False
 
 
 def prompt_user_for_trace_viewing(timeout_seconds: int = 20) -> bool: