{"record":{"id":"c255736150a87e8c","repo":"crewAIInc/crewAI","slug":"error-loading-loader-for-self-e","errorCode":null,"errorMessage":"Error loading loader for {self}: {e}","messagePattern":"Error loading loader for (.+?): (.+?)","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"lib/crewai-tools/src/crewai_tools/rag/data_types.py","lineNumber":95,"sourceCode":"            DataType.YOUTUBE_CHANNEL: (\n                \"youtube_channel_loader\",\n                \"YoutubeChannelLoader\",\n            ),\n            DataType.GITHUB: (\"github_loader\", \"GithubLoader\"),\n            DataType.DOCS_SITE: (\"docs_site_loader\", \"DocsSiteLoader\"),\n            DataType.MYSQL: (\"mysql_loader\", \"MySQLLoader\"),\n            DataType.POSTGRES: (\"postgres_loader\", \"PostgresLoader\"),\n        }\n\n        if self not in loaders:\n            raise ValueError(f\"No loader defined for {self}\")\n        module_name, class_name = loaders[self]\n        module_path = f\"crewai_tools.rag.loaders.{module_name}\"\n        try:\n            module = import_module(module_path)\n            return cast(BaseLoader, getattr(module, class_name)())\n        except Exception as e:\n            raise ValueError(f\"Error loading loader for {self}: {e}\") from e\n\n\nclass DataTypes:\n    @staticmethod\n    def from_content(content: str | Path | None = None) -> DataType:\n        if content is None:\n            return DataType.TEXT\n\n        if isinstance(content, Path):\n            content = str(content)\n\n        is_url = False\n        if isinstance(content, str):\n            try:\n                url = urlparse(content)\n                is_url = bool(url.scheme in (\"http\", \"https\") and url.netloc)\n            except Exception:  # noqa: S110\n                pass","sourceCodeStart":77,"sourceCodeEnd":113,"githubUrl":"https://github.com/crewAIInc/crewAI/blob/754d7323beb2fd042e33444a115ea2d5a47193f0/lib/crewai-tools/src/crewai_tools/rag/data_types.py#L77-L113","documentation":"get_loader() dynamically imports crewai_tools.rag.loaders.<module> and instantiates the loader class; any exception in that process (ModuleNotFoundError for an optional loader dependency such as unstructured, youtube extras, pymysql/psycopg2 for DB loaders, or constructor failure) is wrapped as ValueError('Error loading loader for <DataType>: <cause>').","triggerScenarios":"Selecting a DB loader (MySQLLoader/PostgresLoader) without pymysql/psycopg2 installed; DOCX/PDF loaders requiring unstructured/extra packages; partial installs missing loader submodules.","commonSituations":"Using crewai-tools rag with a niche content type on a slim install; CI images trimmed of optional deps; upgrading crewai-tools changes a loader's dependency set.","solutions":["Read e.__cause__ — it names the missing module or constructor error","Install the specific dependency (e.g. uv add pymysql for MySQLLoader, psycopg2-binary for PostgresLoader)","Reinstall crewai-tools with its rag/reader extras to pull optional deps","Pin versions once working to avoid dependency drift"],"exampleFix":"# before\ntry:\n    loader = dtype.get_loader()\nexcept ValueError:\n    raise\n# after\ntry:\n    loader = dtype.get_loader()\nexcept ValueError as e:\n    cause = str(e.__cause__)\n    logger.error('loader load failed: %s', cause)\n    # e.g. \"No module named 'pymysql'\" -> uv add pymysql\n    raise","handlingStrategy":"try-catch","validationCode":"deps = {DataType.MYSQL: 'pymysql', DataType.POSTGRES: 'psycopg2'}\nimport importlib\nfor dt, mod in deps.items():\n    if dtype == dt:\n        importlib.import_module(mod)  # raises early with the missing module name","typeGuard":null,"tryCatchPattern":"try:\n    loader = dtype.get_loader()\nexcept ValueError as e:\n    cause = str(e.__cause__ or '')\n    if 'No module named' in cause:\n        raise SystemExit(f'missing loader dependency: {cause}') from e\n    raise","preventionTips":["Pre-install dependencies for the loaders your pipeline will use (pymysql, psycopg2-binary, unstructured, etc.)","Smoke-test loader construction at startup","Keep a mapping of DataType -> extra deps in your project setup docs"],"tags":["rag","loader","dependency","dynamic-import"],"backgroundTag":null,"analyzedSha":"754d7323beb2fd042e33444a115ea2d5a47193f0","analyzedAt":"2026-08-15T04:06:56.746Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}