fix(connection): show Klipper's error reason after an E-stop reboot

BlocksScreen/lib/panels/mainWindow.py

@@ -1080,9 +1080,8 @@ def _handle_notify_update_refreshed_message(self, method, data, metadata) -> Non
     @api_handler
     def _handle_printer_message(self, method, data, metadata) -> None:
         """Handle Printer messages"""
-        if "info" in method:
-            # TODO: Handle info
-            ...
+        if "info" in method and isinstance(data, dict):
+            self.conn_window.on_printer_info(data)
         if "print" in method:
             if "start" in method and "ok" in data:
                 self.printer_state_signal.emit("printing")

BlocksScreen/lib/panels/widgets/MainWindow/connectionPage.py

@@ -37,7 +37,7 @@ class ConnectionPage(QtWidgets.QFrame):
         ConnectionState.KLIPPER_STARTUP: "The printer is starting up.\nPlease wait…",
         ConnectionState.KLIPPER_READY: "The printer is ready.",
         ConnectionState.KLIPPER_DISCONNECTED: "The printer is not responding.\nPress 'Restart Printer' to reconnect.",
-        ConnectionState.KLIPPER_ERROR: "A printer error has occurred.\nPress 'Firmware Restart' to recover.",
+        ConnectionState.KLIPPER_ERROR: "A printer error has occurred.\n{message}",
         ConnectionState.KLIPPER_SHUTDOWN: "The printer has shut down.\n{message}",
     }
 
@@ -49,6 +49,13 @@ class ConnectionPage(QtWidgets.QFrame):
         }
     )
 
+    # Any stop before a host reboot (E button, M112, fault) leaves the MCU halted, not only the button
+    _STILL_HALTED: typing.Final[str] = (
+        "Controller board still halted\nfrom a previous stop.\n"
+        "If the emergency button is pressed, release it,\n"
+        "then press 'Firmware Restart' to recover."
+    )
+
     _SHUTDOWN_REASON_MAP: typing.ClassVar[dict[str, str]] = {
         "m112 command": "Emergency stop activated.\nRelease the emergency button, then\npress 'Firmware Restart' to recover.",
         "printers emergency button pressed": "Emergency stop activated.\nRelease the emergency button, then\npress 'Firmware Restart' to recover.",
@@ -64,6 +71,12 @@ class ConnectionPage(QtWidgets.QFrame):
         "protocol error": "MCU communication protocol error.",
         "config error": "Configuration error\nCheck printer.cfg.\nPress 'Firmware Restart' to recover.",
         "mcu error during connect": "Failed to connect to the MCU.",
+        # Klipper error-state first lines (klippy/mcu.py, serialhdl.py, extras/error_mcu.py)
+        "can not update mcu": _STILL_HALTED,
+        "command request": "Emergency stop activated.",
+        "unable to connect": "Cannot reach the controller board.\nCheck its power and USB cable, then\npress 'Firmware Restart'.",
+        "failed automated reset of mcu": "The controller board did not reset.\nPower-cycle the printer.",
+        "mcu protocol error": "Controller board firmware is out of date.\nThe firmware must be updated.",
     }
 
     _FIRMWARE_RESTART_STATES: typing.ClassVar[frozenset[ConnectionState]] = frozenset(
@@ -192,6 +205,8 @@ def _set_state(self, state: ConnectionState, context: str = "") -> None:
             context = (
                 self._last_shutdown_context or ConnectionPage._SHUTDOWN_FALLBACK_CONTEXT
             )
+        elif state == ConnectionState.KLIPPER_ERROR and not context:
+            context = ConnectionPage._SHUTDOWN_FALLBACK_CONTEXT
         if not self._apply_shutdown_guard(state, context):
             return
         if self._handle_pending_restart(state):
@@ -236,11 +251,23 @@ def _update_restart_label(self, state: ConnectionState) -> None:
     @staticmethod
     def _strip_shutdown_prefix(raw: str) -> str:
         return re.sub(
-            r"^(?:Shutdown due to |MCU '[^']*' shutdown[:.]\s*)",
+            r"^(?:Shutdown due to "
+            r"|(?:Previous )?MCU '[^']*' (?:shutdown[:.]|error during config\s*:)\s*"
+            r"|mcu '[^']*'\s*:\s*)",
             "",
             raw.split("\n")[0].strip(),
         )
 
+    @staticmethod
+    def _is_halted_before_start(raw: str) -> bool:
+        # error_mcu.py "Previous" and mcu.py "during config": the MCU stopped before this Klipper run
+        return bool(
+            re.match(
+                r"(?:Previous MCU '[^']*' shutdown|MCU '[^']*' error during config)\s*:",
+                raw.lstrip(),
+            )
+        )
+
     @staticmethod
     def _normalize_shutdown_lines(raw: str) -> str:
         line = ConnectionPage._strip_shutdown_prefix(raw)
@@ -252,10 +279,15 @@ def _clean_shutdown_context(raw: str) -> str:
         lower = ConnectionPage._normalize_shutdown_lines(line)
         if lower in ConnectionPage._SHUTDOWN_NOISE:
             return ""
+        if lower.startswith("command request") and (
+            ConnectionPage._is_halted_before_start(raw)
+        ):
+            return ConnectionPage._STILL_HALTED
         for key, display in ConnectionPage._SHUTDOWN_REASON_MAP.items():
             if lower.startswith(key):
                 return display
-        return line.capitalize()
+        # capitalize() would lowercase pin and MCU names
+        return line[:1].upper() + line[1:]
 
     @staticmethod
     def _build_shutdown_context(raw: str) -> str:
@@ -352,6 +384,18 @@ def webhook_update(self, state: str, message: str) -> None:
                 self._firmware_restarting_pending = True
                 self._restart_10s_timer.start()
                 self._restart_30s_timer.start()
+        elif state == "error":
+            self._set_state(
+                ConnectionState.KLIPPER_ERROR,
+                context=self._build_shutdown_context(message),
+            )
+
+    def on_printer_info(self, info: dict) -> None:
+        """Show the reason from a printer.info reply when Klipper is in error or shutdown."""
+        state = info.get("state")
+        # A shutdown the subscription already reported would cancel the E-stop watchdog
+        if state == "error" or (state == "shutdown" and not self._shutdown_confirmed):
+            self.webhook_update(state, info.get("state_message", ""))
 
     def showEvent(self, a0: QtGui.QShowEvent | None) -> None:
         if self.conn_toggle:

tests/widgets/test_connection_page.py

@@ -247,3 +247,102 @@ def test_unmapped_shutdown_reason_strips_prefix(self, page):
             "Shutdown due to some obscure fault"
         )
         assert result == "Some obscure fault"
+
+
+class TestErrorMessages:
+    # Verbatim Klipper state_message after an E-stop + host reboot (mcu.py + error_mcu.py)
+    MCU_STILL_SHUTDOWN = (
+        "Can not update MCU 'mcu' config as it is shutdown\n"
+        "Once the underlying issue is corrected, use the\n"
+        '"FIRMWARE_RESTART" command to reset the firmware, reload the\n'
+        "config, and restart the host software.\n"
+        "Error configuring printer\n"
+    )
+
+    def test_mcu_still_shutdown_after_reboot(self, page):
+        page.webhook_update("error", self.MCU_STILL_SHUTDOWN)
+        text = page.status_label.text()
+        assert page._state == ConnectionState.KLIPPER_ERROR
+        assert "emergency button" in text
+        assert "Error configuring printer" not in text
+
+    @pytest.mark.parametrize(
+        ("raw", "expected"),
+        [
+            ("mcu 'mcu': Unable to connect", "Cannot reach the controller board"),
+            ("Failed automated reset of MCU 'mcu'", "did not reset"),
+            ("MCU Protocol error\n\nThis is frequently caused", "out of date"),
+        ],
+    )
+    def test_known_error_reasons(self, page, raw, expected):
+        page.webhook_update("error", raw)
+        assert expected in page.status_label.text()
+
+    def test_previous_mcu_shutdown_after_reboot(self, page):
+        # Real order: server.info's bare "shutdown", then the printer.info reply; no subscription
+        page.on_klippy_state("shutdown")
+        page.on_printer_info(
+            {
+                "state": "shutdown",
+                "state_message": "Previous MCU 'mcu' shutdown: Command request\n"
+                "Once the underlying issue is corrected, use the\n"
+                '"FIRMWARE_RESTART" command to reset the firmware',
+            }
+        )
+        assert page._state == ConnectionState.KLIPPER_SHUTDOWN
+        assert "emergency button" in page.status_label.text()
+        assert page._firmware_restarting_pending is False
+
+    def test_error_during_config_after_reboot(self, page):
+        # mcu.py _send_get_config: the other message an E-stop + reboot can produce
+        page.webhook_update("error", "MCU 'mcu' error during config: Command request")
+        assert "emergency button" in page.status_label.text()
+
+    def test_live_command_request_is_not_previous_stop(self, page):
+        page.webhook_update("shutdown", "MCU 'mcu' shutdown: Command request")
+        text = page.status_label.text()
+        assert "Emergency stop activated." in text
+        assert "previous stop" not in text
+
+    def test_unknown_error_keeps_name_case(self, page):
+        page.webhook_update("error", "pin PA1 used multiple times in config")
+        assert "Pin PA1 used multiple times in config" in page.status_label.text()
+
+    def test_unknown_error_shows_klipper_line(self, page):
+        page.webhook_update(
+            "error", "Option 'step_pin' in section 'stepper_x' must be specified"
+        )
+        text = page.status_label.text()
+        assert "step_pin" in text
+        assert "Firmware Restart" in text
+
+    def test_empty_error_keeps_generic_text(self, page):
+        page.webhook_update("error", "")
+        assert page.status_label.text() == (
+            "A printer error has occurred.\nPress 'Firmware Restart' to recover."
+        )
+
+    def test_info_ready_and_startup_are_ignored(self, page):
+        page._set_state(ConnectionState.KLIPPER_ERROR)
+        page.webhook_update("ready", "Printer is ready")
+        page.webhook_update("startup", "Printer is starting")
+        assert page._state == ConnectionState.KLIPPER_ERROR
+
+    def test_printer_info_error_shows_reason(self, page):
+        page.on_printer_info(
+            {"state": "error", "state_message": self.MCU_STILL_SHUTDOWN}
+        )
+        assert "emergency button" in page.status_label.text()
+
+    def test_printer_info_shutdown_keeps_estop_watchdog(self, page):
+        # The info reply to the shutdown transition repeats what the subscription sent
+        estop = "Shutdown due to Printers Emergency Button Pressed."
+        page.webhook_update("shutdown", estop)
+        page.on_printer_info({"state": "shutdown", "state_message": estop})
+        assert page._firmware_restarting_pending is True
+        assert page._restart_30s_timer.isActive()
+
+    @pytest.mark.parametrize("state", ["ready", "startup"])
+    def test_printer_info_non_fault_is_ignored(self, page, state):
+        page.on_printer_info({"state": state, "state_message": "anything"})
+        assert page._state == ConnectionState.DISCONNECTED