Flash around border on exceptions in Scene.embed

manimlib/scene/scene.py

@@ -16,15 +16,18 @@
 from tqdm import tqdm as ProgressDisplay
 
 from manimlib.animation.animation import prepare_animation
+from manimlib.animation.fading import VFadeInThenOut
 from manimlib.camera.camera import Camera
 from manimlib.config import get_module
 from manimlib.constants import ARROW_SYMBOLS
 from manimlib.constants import DEFAULT_WAIT_TIME
 from manimlib.constants import COMMAND_MODIFIER
 from manimlib.constants import SHIFT_MODIFIER
+from manimlib.constants import RED
 from manimlib.event_handler import EVENT_DISPATCHER
 from manimlib.event_handler.event_type import EventType
 from manimlib.logger import log
+from manimlib.mobject.frame import FullScreenRectangle
 from manimlib.mobject.mobject import _AnimationBuilder
 from manimlib.mobject.mobject import Group
 from manimlib.mobject.mobject import Mobject
@@ -34,7 +37,6 @@
 from manimlib.scene.scene_file_writer import SceneFileWriter
 from manimlib.utils.family_ops import extract_mobject_family_members
 from manimlib.utils.family_ops import recursive_mobject_remove
-from manimlib.utils.iterables import list_difference_update
 
 from typing import TYPE_CHECKING
 
@@ -253,14 +255,18 @@ def post_cell_func():
 
         shell.events.register("post_run_cell", post_cell_func)
 
-        if self.embed_error_sound:
-            # Play sound after any Exceptions
-            def custom_exc(shell, etype, evalue, tb, tb_offset=None):
-                # still show the error don't just swallow it
-                shell.showtraceback((etype, evalue, tb), tb_offset=tb_offset)
+        # Flash border, and potentially play sound, on exceptions
+        def custom_exc(shell, etype, evalue, tb, tb_offset=None):
+            # still show the error don't just swallow it
+            shell.showtraceback((etype, evalue, tb), tb_offset=tb_offset)
+            if self.embed_error_sound:
                 os.system("printf '\a'")
+            self.play(VFadeInThenOut(
+                FullScreenRectangle().set_stroke(RED, 30).set_fill(opacity=0),
+                run_time=0.5,
+            ))
 
-            shell.set_custom_exc((Exception,), custom_exc)
+        shell.set_custom_exc((Exception,), custom_exc)
 
         # Set desired exception mode
         shell.magic(f"xmode {self.embed_exception_mode}")