fix debugger detection

rio/session.py

@@ -3130,6 +3130,11 @@ a.remove();
         self,
         properties_to_serialize: IdentityDefaultDict[object, set[str]],
     ):
+        # TODO: This function can probably be optimized in some way. Ideas:
+        # 1. Maintain a permanent `component_level` cache
+        # 2. Find the topmost components at the start and then just iteratively
+        #    yield their children
+
         components_to_build = set[rio.Component]()
         permanent_component_level_cache: dict[rio.Component, int] = {}
 

rio/testing/browser_client.py

@@ -28,7 +28,23 @@ __all__ = ["BrowserClient", "prepare_browser_client"]
 #
 # Note: Chrome's console doesn't show `console.debug` messages per default. To
 # see them, click on "All levels" and check "Verbose".
-DEBUGGER_ACTIVE = sys.gettrace() is not None
+def debugger_active():
+    try:
+        if sys.gettrace() is not None:
+            return True
+    except AttributeError:
+        pass
+
+    try:
+        if sys.monitoring.get_tool(sys.monitoring.DEBUGGER_ID) is not None:  # type: ignore
+            return True
+    except AttributeError:
+        pass
+
+    return False
+
+
+DEBUGGER_ACTIVE = debugger_active()
 
 
 server_manager: ServerManager | None = None