plex deadlock + version showing stale + "disco" screen after docker update fixes

backend/services/preferences_service.py

@@ -40,7 +40,7 @@ class PreferencesService:
         self._settings = settings
         self._config_path = settings.config_file_path
         self._config_cache: Optional[dict] = None
-        self._cache_lock = threading.Lock()
+        self._cache_lock = threading.RLock()
         self._migrate_musicbrainz_settings()
         self._ensure_instance_id()
 

backend/static_server.py

@@ -4,6 +4,9 @@ from fastapi.responses import FileResponse
 from fastapi.staticfiles import StaticFiles
 
 
+_NO_CACHE_HEADERS = {"Cache-Control": "no-cache"}
+
+
 def mount_frontend(app: FastAPI):
     backend_static = Path(__file__).parent / "static"
     frontend_root = Path(__file__).resolve().parents[1] / "frontend"
@@ -83,7 +86,7 @@ def mount_frontend(app: FastAPI):
     @app.get("/")
     async def serve_root():
         if index_html.exists():
-            return FileResponse(index_html)
+            return FileResponse(index_html, headers=_NO_CACHE_HEADERS)
         raise HTTPException(status_code=404, detail="Frontend not built yet")
 
     @app.get("/{full_path:path}")
@@ -91,5 +94,5 @@ def mount_frontend(app: FastAPI):
         if full_path.startswith("api"):
             raise HTTPException(status_code=404, detail="API route not found")
         if index_html.exists():
-            return FileResponse(index_html)
+            return FileResponse(index_html, headers=_NO_CACHE_HEADERS)
         raise HTTPException(status_code=404, detail="Frontend not built yet")

backend/tests/routes/test_plex_auth.py

@@ -77,6 +77,43 @@ class TestCreatePlexPin:
         assert resp.status_code == 500
 
 
+class TestGetOrCreateSettingNoDeadlock:
+    def test_get_or_create_setting_does_not_deadlock(self, tmp_path):
+        import threading
+
+        from core.config import Settings
+        from services.preferences_service import PreferencesService
+
+        config_path = tmp_path / "config.json"
+        settings = Settings(
+            root_app_dir=tmp_path,
+            config_file_path=config_path,
+            cache_dir=tmp_path / "cache",
+            library_db_path=tmp_path / "cache" / "library.db",
+            queue_db_path=tmp_path / "cache" / "queue.db",
+        )
+
+        result = None
+        exc = None
+
+        def run():
+            nonlocal result, exc
+            try:
+                prefs = PreferencesService(settings)
+                result = prefs.get_or_create_setting("plex_client_id", lambda: "test-client-id")
+                result = (result, prefs.get_or_create_setting("plex_client_id", lambda: "other"))
+            except Exception as e:
+                exc = e
+
+        t = threading.Thread(target=run)
+        t.start()
+        t.join(timeout=5)
+        assert not t.is_alive(), "Deadlock detected: PreferencesService hung for 5s"
+        assert exc is None
+        assert result[0] == "test-client-id"
+        assert result[1] == "test-client-id"
+
+
 class TestPollPlexPin:
     def test_poll_pending(self, auth_client):
         resp = auth_client.get("/plex/auth/poll?pin_id=12345")

frontend/src/lib/queries/VersionQuery.svelte.ts

@@ -30,7 +30,8 @@ export const getVersionQuery = () =>
 		staleTime: CACHE_TTL.VERSION_INFO,
 		queryKey: VersionQueryKeyFactory.info(),
 		queryFn: ({ signal }) => api.global.get<VersionInfo>(API.version.info(), { signal }),
-		refetchOnWindowFocus: false
+		refetchOnWindowFocus: false,
+		refetchOnMount: 'always'
 	}));
 
 export const getUpdateCheckQuery = () =>

frontend/src/routes/+error.svelte

@@ -0,0 +1,28 @@
+<script lang="ts">
+	import { AlertTriangle, Home, RotateCw } from 'lucide-svelte';
+	import { page } from '$app/state';
+</script>
+
+<svelte:head>
+	<title>Error - MusicSeerr</title>
+</svelte:head>
+
+<div class="w-full px-2 sm:px-4 lg:px-8 py-4 sm:py-8 max-w-7xl mx-auto">
+	<div class="flex flex-col items-center justify-center py-20 gap-4 text-center">
+		<AlertTriangle class="h-16 w-16 text-error/40" />
+		<h1 class="text-lg font-semibold text-base-content/80">Something went wrong</h1>
+		<p class="text-sm text-base-content/60">
+			{page.error?.message ?? 'An unexpected error occurred'}
+		</p>
+		<div class="flex items-center gap-2">
+			<a href="/" class="btn btn-ghost btn-sm">
+				<Home class="h-4 w-4" />
+				Home
+			</a>
+			<button class="btn btn-accent btn-sm" onclick={() => location.reload()}>
+				<RotateCw class="h-4 w-4" />
+				Retry
+			</button>
+		</div>
+	</div>
+</div>