better rich.traceback initialization

bin/key-mapper-gtk

@@ -36,14 +36,6 @@ from keymapper.gtk.window import Window
 from keymapper.daemon import Daemon
 
 
-try:
-    from rich.traceback import install
-    install(show_locals=True)
-except Exception:
-    # since this is optional, just skip all exceptions
-    pass
-
-
 if __name__ == '__main__':
     parser = ArgumentParser()
     parser.add_argument(

bin/key-mapper-service

@@ -37,14 +37,6 @@ from keymapper.daemon import Daemon, BUS_NAME
 from keymapper.dev.permissions import can_read_devices
 
 
-try:
-    from rich.traceback import install
-    install(show_locals=True)
-except Exception:
-    # since this is optional, just skip all exceptions
-    pass
-
-
 if __name__ == '__main__':
     parser = ArgumentParser()
     parser.add_argument(

keymapper/logger.py

@@ -118,9 +118,21 @@ def log_info():
 
 
 def update_verbosity(debug):
-    """Set the logging verbosity according to the settings object."""
+    """Set the logging verbosity according to the settings object.
+
+    Also enable rich tracebacks in debug mode.
+    """
     if debug:
         logger.setLevel(SPAM)
+
+        try:
+            from rich.traceback import install
+            install(show_locals=True)
+            logger.debug('Using rich.traceback')
+        except Exception as error:
+            # since this is optional, just skip all exceptions
+            if not isinstance(error, ImportError):
+                logger.debug(f'Cannot use rich.traceback: {error}')
     else:
         logger.setLevel(logging.INFO)