fix(record): surface detailed recording errors and hardware hints to the GUI

frontend/src/pages/Recording.tsx

@@ -72,6 +72,8 @@ interface BackendStatus {
     exit_early: boolean;
     rerecord_episode: boolean;
   };
+  error?: string | null;
+  hint?: string | null;
 }
 
 const Recording = () => {
@@ -88,6 +90,7 @@ const Recording = () => {
     null
   );
   const [recordingSessionStarted, setRecordingSessionStarted] = useState(false);
+  const [sessionError, setSessionError] = useState<{ error: string; hint: string | null } | null>(null);
 
   const [optimisticPhase, setOptimisticPhase] = useState<Phase | null>(null);
   const [showStopConfirm, setShowStopConfirm] = useState(false);
@@ -141,7 +144,7 @@ const Recording = () => {
 
   // Poll backend status continuously to stay in sync
   useEffect(() => {
-    if (!recordingSessionStarted) return;
+    if (!recordingSessionStarted || sessionError !== null) return;
 
     const pollStatus = async () => {
       try {
@@ -150,6 +153,15 @@ const Recording = () => {
         );
         if (!response.ok) return;
         const status = await response.json();
+
+        if (status.current_phase === "error" && status.session_ended) {
+          setSessionError({
+            error: status.error || "Recording session failed.",
+            hint: status.hint || null,
+          });
+          return;
+        }
+
         setBackendStatus(status);
 
         const currentOptimistic = optimisticPhaseRef.current;
@@ -205,7 +217,7 @@ const Recording = () => {
     pollStatus();
     const statusInterval = setInterval(pollStatus, 1000);
     return () => clearInterval(statusInterval);
-  }, [recordingSessionStarted, recordingConfig, navigate, baseUrl, fetchWithHeaders]);
+  }, [recordingSessionStarted, recordingConfig, navigate, baseUrl, fetchWithHeaders, sessionError]);
 
   const formatTime = (seconds: number): string => {
     const mins = Math.floor(seconds / 60);
@@ -597,6 +609,39 @@ const Recording = () => {
           </AlertDialogFooter>
         </AlertDialogContent>
       </AlertDialog>
+
+      <AlertDialog open={sessionError !== null}>
+        <AlertDialogContent className="bg-gray-900 border-gray-700 text-white max-w-lg">
+          <AlertDialogHeader>
+            <AlertDialogTitle className="text-red-500 flex items-center gap-2">
+              <span className="w-2.5 h-2.5 rounded-full bg-red-500 animate-ping" />
+              Recording Session Failed
+            </AlertDialogTitle>
+            <AlertDialogDescription className="text-gray-300 space-y-4 mt-2">
+              <p>The recording session encountered an error and had to stop.</p>
+
+              <div className="bg-black/50 p-4 rounded border border-red-900/50 font-mono text-xs text-red-400 max-h-40 overflow-y-auto break-all whitespace-pre-wrap">
+                {sessionError?.error}
+              </div>
+
+              {sessionError?.hint && (
+                <div className="bg-blue-950/40 p-4 rounded border border-blue-800/40 text-sm text-slate-200">
+                  <strong className="text-blue-400 block mb-1">Hardware Hint:</strong>
+                  {sessionError.hint}
+                </div>
+              )}
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogAction
+              onClick={() => navigate("/")}
+              className="bg-red-600 hover:bg-red-700 text-white"
+            >
+              Return to Home
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
     </div>
   );
 };

lelab/record.py

@@ -31,7 +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
+from .utils.devices import friendly_hint, safe_disconnect_device
 
 logger = logging.getLogger(__name__)
 
@@ -409,10 +409,19 @@ def handle_recording_status() -> dict[str, Any]:
             logger.info("📡 RECORDING STATUS REQUEST: Session has ended - frontend should stop polling")
             print("📡 STATUS CHANGE: Frontend is still polling after session end - should stop now")
 
+    error = None
+    hint = None
+    if current_phase == "error" and last_recording_info is not None:
+        error = last_recording_info.get("error")
+        if error:
+            hint = friendly_hint(error)
+
     status = {
         "recording_active": recording_active,
         "current_phase": current_phase,  # "preparing", "recording", "resetting", "completed"
         "session_ended": session_ended,  # New field to indicate session completion
+        "error": error,
+        "hint": hint,
         "available_controls": {
             "stop_recording": recording_active,  # ESC key replacement
             "exit_early": recording_active,  # Right arrow key replacement

lelab/rollout.py

@@ -37,6 +37,7 @@
 from pydantic import BaseModel
 
 from .utils.config import setup_follower_calibration_file
+from .utils.devices import friendly_hint
 
 logger = logging.getLogger(__name__)
 
@@ -185,34 +186,6 @@ def _extract_error_from_log(log_path: str | None) -> str | None:
     return snippet or None
 
 
-def _friendly_hint(error_text: str | None) -> str | None:
-    """A plain-language, actionable headline for the common SO-101 failures."""
-    if not error_text:
-        return None
-    low = error_text.lower()
-    if "overload" in low or "torque_enable" in low:
-        return (
-            "A motor overloaded — usually the gripper holding an object too hard. Release the object / "
-            "open the gripper and power-cycle the arm before trying again."
-        )
-    if "missing motor ids" in low or "motor check failed" in low:
-        return (
-            "A follower motor isn't responding (often the gripper, id 6). If a skill was holding an object "
-            "it likely overloaded — remove it, power-cycle the arm, then try teleoperation first."
-        )
-    if "could not connect" in low or "failed to connect" in low or "not connected" in low:
-        return "Couldn't connect to the arm — make sure it's plugged in, powered on, and on the right port."
-    if "frame is too old" in low or "no frame" in low or "frame timeout" in low:
-        return (
-            "A camera can't keep up — frames are arriving too slowly. Lower its resolution/FPS, "
-            "set FOURCC=MJPG, and close other heavy apps, then try again."
-        )
-    if "failed to set capture_" in low or "actual_width" in low or "actual_height" in low:
-        return "A camera doesn't support the configured resolution — open camera settings and click Auto."
-    if "permission" in low and ("port" in low or "com" in low):
-        return "Couldn't open the serial port — close anything else using it, or run `lelab --stop`."
-    return None
-
 
 # Errors that mean the policy actually ran and only shutdown/cleanup tripped —
 # e.g. disabling torque on a gripper still holding an object. Connection-loss
@@ -400,7 +373,7 @@ def handle_inference_status() -> dict[str, Any]:
                 "exit_code": rc,
                 "outcome": outcome,
                 "error": error,
-                "hint": _friendly_hint(error),
+                "hint": friendly_hint(error),
                 "policy_ref": finished_meta.get("policy_ref"),
                 "duration_s": finished_meta.get("duration_s"),
                 "log_path": finished_meta.get("log_path"),

lelab/server.py

@@ -1019,9 +1019,55 @@ def _v4l2_camera_name(index: int) -> str | None:
         return None
 
 
-def _linux_cameras() -> list[dict[str, Any]]:
+def _chrome_camera_name(index: int) -> str | None:
+    import os
+    import re
+
+    # 기본 v4l2_name 불러오기
+    v4l2_name = _v4l2_camera_name(index)
+
+    try:
+        sys_path = f"/sys/class/video4linux/video{index}"
+        current_dir = os.path.join(sys_path, "device")
+
+        for _ in range(5):
+            vid_path = os.path.join(current_dir, "idVendor")
+            pid_path = os.path.join(current_dir, "idProduct")
+            product_path = os.path.join(current_dir, "product")
+
+            # vender id 와 product id가 있다면
+            if os.path.exists(vid_path) and os.path.exists(pid_path):
+                try:
+                    with open(vid_path, "r", encoding="utf-8") as f:
+                        vid = f.read().strip()
+                    with open(pid_path, "r", encoding="utf-8") as f:
+                        pid = f.read().strip()
+
+                    if os.path.exists(product_path):
+                        with open(product_path, "r", encoding="utf-8") as f:
+                            base_name = f.read().strip()
+                    else:
+                        base_name = v4l2_name.split(":")[0].strip()
+
+                    # 크롬 브라우저 포맷으로 이름 조합
+                    base_name = base_name.replace("_", " ")
+                    base_name = re.sub(r'\s+HD$', '', base_name).strip()
+                    return f"{base_name} ({vid}:{pid})"
+                except Exception:
+                    return v4l2_name
+            # 찾는게 없으면 상위 폴더로 이동    
+            current_dir = os.path.join(current_dir, "..")
+
+        # 5단계를 거슬러 올라가도 못 찾으면 원래 이름 반환
+        return v4l2_name    
+    except OSError:
+        return None
+
+def _linux_cameras(is_chrome: bool = False) -> list[dict[str, Any]]:
     """Enumerate Linux cameras, naming each from sysfs (no extra deps)."""
     import cv2
+    import os
+    import re
 
     cameras: list[dict[str, Any]] = []
     for i in range(10):
@@ -1030,12 +1076,16 @@ def _linux_cameras() -> list[dict[str, Any]]:
         cap.release()
         if not opened:
             continue
-        cameras.append({"index": i, "name": _v4l2_camera_name(i) or f"Camera {i}", "available": True})
+
+        if is_chrome:
+            cameras.append({"index": i, "name": _chrome_camera_name(i) or f"Camera {i}", "available": True})
+        else:
+            cameras.append({"index": i, "name": _v4l2_camera_name(i) or f"Camera {i}", "available": True})
     return cameras
 
 
 @app.get("/available-cameras")
-def get_available_cameras():
+def get_available_cameras(request: Request):
     """List cameras with the same index ordering cv2 will use to record.
 
     Each platform enumerates in the order its cv2 backend indexes devices, and
@@ -1051,6 +1101,10 @@ def get_available_cameras():
         import platform
 
         system = platform.system()
+
+        # User-Agent를 확인하여 크롬(크로미움 기반) 브라우저인지 판별
+        user_agent = request.headers.get("user-agent", "").lower()
+        is_chrome = "chrome" in user_agent
 
         if system == "Darwin":
             cameras = _avfoundation_cameras_in_cv2_order()
@@ -1060,7 +1114,7 @@ def get_available_cameras():
         if system == "Windows":
             return {"status": "success", "cameras": _windows_cameras()}
         if system == "Linux":
-            return {"status": "success", "cameras": _linux_cameras()}
+            return {"status": "success", "cameras": _linux_cameras(is_chrome=is_chrome)}
 
         import cv2
 

lelab/teleoperate.py

@@ -97,13 +97,13 @@ def get_joint_positions_from_robot(robot) -> dict[str, float]:
 
             raw_deg = observation[motor_key]
             angle_degrees = raw_deg
-            correction = _SO101_URDF_CORRECTIONS.get(motor_name)
-            if correction is not None and motor_name in calibration:
-                sign, urdf_zero_ticks = correction
-                cal = calibration[motor_name]
-                mid = (cal.range_min + cal.range_max) / 2
-                motor_at_urdf_zero = (urdf_zero_ticks - mid) * 360 / _STS3215_MAX_RES
-                angle_degrees = sign * (raw_deg - motor_at_urdf_zero)
+            #correction = _SO101_URDF_CORRECTIONS.get(motor_name)
+            #if correction is not None and motor_name in calibration:
+            #    sign, urdf_zero_ticks = correction
+            #    cal = calibration[motor_name]
+            #    mid = (cal.range_min + cal.range_max) / 2
+            #    motor_at_urdf_zero = (urdf_zero_ticks - mid) * 360 / _STS3215_MAX_RES
+            #    angle_degrees = sign * (raw_deg - motor_at_urdf_zero)
 
             joint_positions[urdf_joint_name] = angle_degrees * math.pi / 180.0
             debug_rows.append(

lelab/utils/devices.py

@@ -49,3 +49,33 @@ def _force_close_device_resources(device: Any, logger: logging.Logger) -> None:
                 cam.disconnect()
             except Exception as exc:
                 logger.warning("Failed to disconnect camera after device cleanup failure: %s", exc)
+
+
+def friendly_hint(error_text: str | None) -> str | None:
+    """A plain-language, actionable headline for the common SO-101 failures."""
+    if not error_text:
+        return None
+    low = error_text.lower()
+    if "overload" in low or "torque_enable" in low:
+        return (
+            "A motor overloaded — usually the gripper holding an object too hard. Release the object / "
+            "open the gripper and power-cycle the arm before trying again."
+        )
+    if "missing motor ids" in low or "motor check failed" in low:
+        return (
+            "A follower motor isn't responding (often the gripper, id 6). If a skill was holding an object "
+            "it likely overloaded — remove it, power-cycle the arm, then try teleoperation first."
+        )
+    if "could not connect" in low or "failed to connect" in low or "not connected" in low:
+        return "Couldn't connect to the arm — make sure it's plugged in, powered on, and on the right port."
+    if "frame is too old" in low or "no frame" in low or "frame timeout" in low:
+        return (
+            "A camera can't keep up — frames are arriving too slowly. Lower its resolution/FPS, "
+            "set FOURCC=MJPG, and close other heavy apps, then try again."
+        )
+    if "failed to set capture_" in low or "actual_width" in low or "actual_height" in low:
+        return "A camera doesn't support the configured resolution — open camera settings and click Auto."
+    if "permission" in low and ("port" in low or "com" in low):
+        return "Couldn't open the serial port — close anything else using it, or run `lelab --stop`."
+    return None
+