Ignore failures to beep

kitty/window.py

@@ -108,8 +108,11 @@ class Window:
         wakeup()
 
     def bell(self):
-        with open('/dev/tty', 'wb') as f:
-            f.write(b'\007')
+        try:
+            with open('/dev/tty', 'wb') as f:
+                f.write(b'\007')
+        except EnvironmentError:
+            pass  # failure to beep is not critical
         if self.opts.visual_bell_duration > 0:
             self.start_visual_bell_at = monotonic()
             glfw_post_empty_event()