fix(devices): force-release camera/serial in recording and calibration teardown

lelab/calibrate.py

@@ -38,6 +38,8 @@
 )
 from lerobot.utils.utils import init_logging
 
+from .utils.devices import safe_disconnect_device
+
 logger = logging.getLogger(__name__)
 
 
@@ -523,14 +525,16 @@ def _cleanup_and_finish(self, message: str, status: str = "completed"):
         self._update_status(calibration_active=False, status=status, message=message)
 
     def _cleanup_device(self):
-        """Clean up device connection"""
-        try:
-            if self.device:
-                logger.info("Disconnecting device...")
-                self.device.disconnect()
-                self.device = None
-        except Exception as e:
-            logger.error(f"Error disconnecting device: {e}")
+        """Clean up device connection.
+
+        Uses safe_disconnect_device so a failed disconnect (flaky USB/serial)
+        force-releases the port/cameras instead of leaving the device busy and
+        blocking the next calibration/teleop/record run.
+        """
+        if self.device:
+            logger.info("Disconnecting device...")
+            safe_disconnect_device(self.device, logger, context="calibration cleanup")
+            self.device = None
 
 
 # Global calibration manager instance

lelab/record.py

@@ -31,6 +31,7 @@
 from lerobot.teleoperators.so_leader import SO101LeaderConfig
 
 from .utils.config import setup_calibration_files, with_lelab_tag
+from .utils.devices import safe_disconnect_device
 
 logger = logging.getLogger(__name__)
 
@@ -862,9 +863,12 @@ def record_with_web_events(cfg: RecordConfig, web_events: dict) -> LeRobotDatase
         log_say("Stop recording", cfg.play_sounds, blocking=True)
 
     finally:
-        robot.disconnect()
+        # safe_disconnect_device force-releases the serial port / cameras if a
+        # normal disconnect fails, so a flaky teardown can't leave the device
+        # busy and block the next recording session (see issue #50).
+        safe_disconnect_device(robot, logger, context="recording cleanup")
         if teleop:
-            teleop.disconnect()
+            safe_disconnect_device(teleop, logger, context="recording cleanup")
 
     if cfg.dataset.push_to_hub:
         dataset.push_to_hub(tags=cfg.dataset.tags, private=cfg.dataset.private)

tests/test_calibrate.py

@@ -72,3 +72,32 @@ def test_calibration_manager_rejects_double_start_via_message() -> None:
     )
     assert result.get("success") is False
     assert "already" in result.get("message", "").lower()
+
+
+def test_cleanup_device_force_releases_and_clears_when_disconnect_fails() -> None:
+    """A failed device.disconnect() must still force-close the port and clear the
+    device handle — otherwise the COM port stays busy and blocks the next run."""
+    from lelab.calibrate import CalibrationManager
+
+    class PortHandler:
+        def __init__(self) -> None:
+            self.closed = False
+
+        def closePort(self) -> None:  # noqa: N802 - mirrors LeRobot port handler API
+            self.closed = True
+
+    class Device:
+        def __init__(self) -> None:
+            self.bus = type("Bus", (), {"port_handler": PortHandler()})()
+
+        def disconnect(self) -> None:
+            raise RuntimeError("Failed to write 'Torque_Enable' on id_=6")
+
+    mgr = CalibrationManager()
+    device = Device()
+    mgr.device = device
+
+    mgr._cleanup_device()
+
+    assert device.bus.port_handler.closed is True  # force-released despite failure
+    assert mgr.device is None  # handle cleared so a new calibration can start