{"record":{"id":"e6f0461980a8933c","repo":"langchain-ai/deepagents","slug":"context-hub-cache-failed-to-initialize","errorCode":null,"errorMessage":"Context Hub cache failed to initialize","messagePattern":"Context Hub cache failed to initialize","errorType":"exception","errorClass":"RuntimeError","httpStatus":null,"severity":"error","filePath":"libs/deepagents/deepagents/backends/context_hub.py","lineNumber":150,"sourceCode":"            if isinstance(entry, FileEntry):\n                cache[path] = entry.content\n            else:\n                linked_entries[path] = entry.repo_handle\n        return cache, linked_entries, context.commit_hash\n\n    def _load_tree_locked(self) -> None:\n        cache, linked_entries, commit_hash = self._fetch_tree()\n        self._cache = cache\n        self._linked_entries = linked_entries\n        self._commit_hash = commit_hash\n\n    def _ensure_cache_locked(self) -> dict[str, str]:\n        if self._cache is None:\n            # The state lock makes the cold remote pull single-flight.\n            self._load_tree_locked()\n        if self._cache is None:\n            msg = \"Context Hub cache failed to initialize\"\n            raise RuntimeError(msg)\n        return self._cache\n\n    @staticmethod\n    def _overlay(cache: dict[str, str], changes: dict[str, str | None]) -> None:\n        for path, content in changes.items():\n            if content is None:\n                cache.pop(path, None)\n            else:\n                cache[path] = content\n\n    def _visible_cache_locked(self) -> dict[str, str]:\n        visible = dict(self._ensure_cache_locked())\n        for mutations in (self._mutations.in_flight, self._mutations.pending):\n            for mutation in mutations:\n                self._overlay(visible, mutation.changes)\n        return visible\n\n    def _ensure_cache(self) -> dict[str, str]:","sourceCodeStart":132,"sourceCodeEnd":168,"githubUrl":"https://github.com/langchain-ai/deepagents/blob/a1af029e6e73cb17c36bff823d227747b28e91e1/libs/deepagents/deepagents/backends/context_hub.py#L132-L168","documentation":"`ContextHubBackend._ensure_cache_locked` lazily loads the remote tree into an in-memory cache under the state lock; if after `_load_tree_locked()` the cache is still `None`, initialization failed silently and it raises `RuntimeError`. Any cache-reading or mutation-draining path depends on this cache being present.","triggerScenarios":"Calling `get_linked_entries`, `has_prior_commits`, `_submit_changes`, `_complete_batch`, or reading the visible cache when the cold remote pull (`_load_tree_locked`) fails to populate `self._cache` — e.g. remote store unreachable or returns an empty/unexpected tree.","commonSituations":"Network/auth failures talking to the Context Hub remote on first use; misconfigured remote URL/credentials; remote project/tree deleted or never initialized.","solutions":["Check connectivity/auth to the Context Hub remote and retry the operation.","Verify the remote tree/project exists and is initialized before using the backend.","Inspect `_load_tree_locked` failure paths/logs to find why the pull produced no cache, and fix the underlying load error."],"exampleFix":"// before: uninitialized remote\nbackend = ContextHubBackend(remote=\"https://hub.example.com/missing-project\")\n// after: ensure the project/tree is initialized first\ncreate_remote_tree(remote=\"https://hub.example.com/my-project\")\nbackend = ContextHubBackend(remote=\"https://hub.example.com/my-project\")","handlingStrategy":"retry","validationCode":"# ensure the remote tree is reachable and initialized before constructing the backend\nassert remote_tree_exists(hub_url, project), \"Context Hub remote tree missing/uninitialized\"","typeGuard":null,"tryCatchPattern":"for attempt in range(3):\n    try:\n        entries = backend.get_linked_entries(key)\n        break\n    except RuntimeError as e:\n        if \"cache failed to initialize\" not in str(e) or attempt == 2:\n            raise\n        time.sleep(0.5 * (attempt + 1))","preventionTips":["Verify remote URL/credentials and tree initialization at startup with a health check.","Monitor network/auth failures to the Context Hub remote; alert before agents run.","Log failures inside the cold-pull path so init failures are diagnosable."],"tags":["context-hub","cache","initialization","remote"],"backgroundTag":"cache-initialization-failed","analyzedSha":"a1af029e6e73cb17c36bff823d227747b28e91e1","analyzedAt":"2026-08-29T11:43:24.718Z","schemaVersion":2},"datasetVersion":"2026-08-29T12:17:43.993Z"}