Fix fatal crash on Windows when window title matches MIDI loopback device name

midimech.py

@@ -52,13 +52,23 @@ def main():
     try:
         core = Core()
         core()
-    except SystemExit:
-        pass
+    except SystemExit as e:
+        if e.code != 0:
+            print(f"midimech exited with code {e.code}")
     except:
         print(traceback.format_exc())
-    del core
-    pygame.midi.quit()
-    pygame.display.quit()
+    try:
+        del core
+    except:
+        pass
+    try:
+        pygame.midi.quit()
+    except:
+        pass
+    try:
+        pygame.display.quit()
+    except:
+        pass
     os._exit(0)
     # pygame.quit()
 

src/constants.py

@@ -1,6 +1,9 @@
 from glm import ivec2, vec2, ivec3, vec3
 
-TITLE = "midimech"
+# Window title must not exactly match the "midimech" MIDI loopback device name.
+# On some Windows setups, SDL fatally terminates the process when the window
+# title matches a MIDI device name (case-insensitive). Exact cause unknown.
+TITLE = "midimech app"
 # FOCUS = False
 NOTES = ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"]
 WHOLETONE = True

src/core.py

@@ -924,6 +924,15 @@ def note_off(self, data, timestamp, width=None, mpe=None, octave=0, transpose=0,
 
     def cb_midi_in(self, data, timestamp, force_channel=None):
         """LinnStrument MIDI Callback"""
+        if not hasattr(self, 'board'):
+            return  # not fully initialized yet
+        try:
+            self._cb_midi_in(data, timestamp, force_channel)
+        except Exception as e:
+            print(f"MIDI callback error: {e}")
+
+    def _cb_midi_in(self, data, timestamp, force_channel=None):
+        """LinnStrument MIDI Callback (inner)"""
         # d4 = None
         # if len(data)==4:
         #     d4 = data[3]