The debug statement had an incorrect formatter

ardupilot_methodic_configurator/backend_flightcontroller_connection.py

@@ -393,7 +393,7 @@ def _select_supported_autopilot(self, detected_vehicles: dict[tuple[int, int], A
         for (sysid, compid), m in detected_vehicles.items():
             self.info.set_system_id_and_component_id(str(sysid), str(compid))
             logging_debug(
-                _("Connection established with systemID %d, componentID %d."), self.info.system_id, self.info.component_id
+                _("Connection established with systemID %s, componentID %s."), self.info.system_id, self.info.component_id
             )
             self.info.set_autopilot(m.autopilot)
             if self.info.is_supported:

ardupilot_methodic_configurator/frontend_tkinter_usage_popup_window.py

@@ -21,10 +21,7 @@
 from ardupilot_methodic_configurator.backend_filesystem import LocalFilesystem
 from ardupilot_methodic_configurator.backend_filesystem_program_settings import ProgramSettings
 from ardupilot_methodic_configurator.frontend_tkinter_base_window import BaseWindow
-from ardupilot_methodic_configurator.frontend_tkinter_font import (
-    create_scaled_font,
-    get_safe_font_config,
-)
+from ardupilot_methodic_configurator.frontend_tkinter_font import create_scaled_font, get_safe_font_config
 from ardupilot_methodic_configurator.frontend_tkinter_rich_text import RichText
 
 
@@ -100,11 +97,19 @@ def finalize_setup_popupwindow(
             BaseWindow.center_window(popup_window.root, parent)
         # For parent-less, center on screen
 
-        popup_window.root.deiconify()  # Show the window now that it's positioned
-        popup_window.root.attributes("-topmost", True)  # noqa: FBT003
-        popup_window.root.grab_set()  # Make the popup modal
-
-        popup_window.root.protocol("WM_DELETE_WINDOW", close_callback)
+        try:
+            # Show the window now that it's positioned. Calls may fail if the
+            # main application has been destroyed (for example during shutdown)
+            # — guard against tk.TclError so the caller doesn't crash the app.
+            popup_window.root.deiconify()
+            popup_window.root.attributes("-topmost", True)  # noqa: FBT003
+            popup_window.root.grab_set()  # Make the popup modal
+
+            popup_window.root.protocol("WM_DELETE_WINDOW", close_callback)
+        except tk.TclError:
+            # Application / interpreter has been destroyed or the underlying
+            # Tk root is no longer available; there's nothing more to do.
+            pass
 
     @staticmethod
     def close(popup_window: BaseWindow, parent: Optional[tk.Tk]) -> None:

tests/test_backend_flightcontroller_connection.py

@@ -17,6 +17,7 @@
 
 import pytest
 import serial.tools.list_ports_common
+from pymavlink import mavutil
 
 from ardupilot_methodic_configurator.backend_flightcontroller_connection import (
     DEFAULT_BAUDRATE,
@@ -33,7 +34,7 @@
 )
 from ardupilot_methodic_configurator.data_model_flightcontroller_info import FlightControllerInfo
 
-# pylint: disable=protected-access
+# pylint: disable=protected-access, too-many-lines
 
 
 class TestFlightControllerConnectionServiceInjection:
@@ -982,5 +983,35 @@ def test_connection_comport_attribute_lifecycle(self) -> None:
         assert connection.comport is None
 
 
+def test_select_supported_autopilot_with_string_ids_does_not_raise() -> None:
+    """
+    Ensure that system/component IDs stored as strings do not cause logging to raise (previously %d was used).
+
+    This is to prevent future regressions
+    GIVEN: FlightControllerConnection and a detected vehicle
+    WHEN: _select_supported_autopilot is called and FlightControllerInfo stores
+          string IDs
+    THEN: The function returns success and does not raise
+    """
+    connection = FlightControllerConnection(info=FlightControllerInfo())
+
+    # Minimal dummy heartbeat message - use supported autopilot constant
+    class DummyHeartbeat:  # pylint: disable=too-few-public-methods
+        """Dummy MAVLink heartbeat used as input to _select_supported_autopilot."""
+
+        autopilot = mavutil.mavlink.MAV_AUTOPILOT_ARDUPILOTMEGA
+        type = mavutil.mavlink.MAV_TYPE_GROUND_ROVER
+
+    dummy = DummyHeartbeat()
+
+    # Call with integer keys (function converts to strings internally) and ensure no exception
+    result = connection._select_supported_autopilot({(1, 1): dummy})
+
+    # Successful selection returns empty string and system/component IDs are stored as strings
+    assert result == ""
+    assert connection.info.system_id == "1"
+    assert connection.info.component_id == "1"
+
+
 if __name__ == "__main__":
     pytest.main([__file__, "-v"])

tests/test_frontend_tkinter_usage_popup_window.py

@@ -14,7 +14,7 @@
 import sys
 import tkinter as tk
 from tkinter import ttk
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock, Mock, patch
 
 import pytest
 
@@ -581,5 +581,39 @@ def test_confirmation_popup_defaults_to_false_when_closed(
             assert result is False, "Should default to False when closed without confirmation"
 
 
+def test_finalize_setup_popupwindow_handles_destroyed_tk() -> None:
+    """Ensure finalize_setup_popupwindow doesn't raise if Tk has been destroyed and deiconify() raises tk.TclError."""
+
+    class FakePopup:  # pylint: disable=too-few-public-methods
+        """Fake popup window simulating destroyed Tk."""
+
+        def __init__(self) -> None:
+            self.root = Mock()
+            # Minimal methods used by finalize_setup_popupwindow
+            self.root.update_idletasks = Mock(return_value=None)
+            self.root.winfo_reqheight = Mock(return_value=10)
+            self.root.winfo_reqwidth = Mock(return_value=20)
+            self.root.geometry = Mock()
+
+            # Simulate a destroyed Tk: deiconify raises TclError
+            self.root.deiconify = Mock(side_effect=tk.TclError("application has been destroyed"))
+            # These should not be invoked after deiconify fails
+            self.root.attributes = Mock()
+            self.root.grab_set = Mock()
+            self.root.protocol = Mock()
+
+    fake = FakePopup()
+
+    # Should not raise even though deiconify raises
+    PopupWindow.finalize_setup_popupwindow(fake, parent=None, close_callback=lambda: None)
+
+    # deiconify was attempted
+    fake.root.deiconify.assert_called_once()
+    # attributes/grab_set/protocol should not be called because deiconify failed
+    assert not fake.root.attributes.called
+    assert not fake.root.grab_set.called
+    assert not fake.root.protocol.called
+
+
 if __name__ == "__main__":
     pytest.main([__file__, "-v"])