crewAIInc/crewAI · error · RuntimeError

Pool lock not initialized

Error message

Pool lock not initialized

What it means

SnowflakeSearchTool._get_connection raises RuntimeError("Pool lock not initialized") when self._pool_lock is None. The lock (and pool) are only created in the dependency-bootstrap path inside __init__ when packages are present; if initialization was skipped or interrupted, async connection acquisition refuses to proceed rather than racing on an unprotected pool.

Solutions

1. Ensure the Snowflake dependencies are installed BEFORE constructing the tool so __init__ fully initializes the pool, lock, and thread pool.
2. Do not catch-and-continue around tool construction — the ImportError at init is the root cause; fix it instead.
3. Recreate the SnowflakeSearchTool instance if its state was cleared rather than reusing it.

Example fix

# before
try:
    tool = SnowflakeSearchTool(config=cfg)
except ImportError:
    pass  # later: await tool._get_connection() -> RuntimeError

# after
# pip install snowflake-connector-python snowflake-sqlalchemy cryptography
tool = SnowflakeSearchTool(config=cfg)

tool = SnowflakeSearchTool(config=cfg)  # raises ImportError if deps missing
if getattr(tool, "_pool_lock", None) is None:
    raise RuntimeError("Tool not fully initialized; install Snowflake dependencies and recreate")

try:
    conn = await tool._get_connection()
except RuntimeError as e:
    if "not initialized" in str(e):
        tool = SnowflakeSearchTool(config=cfg)  # recreate after fixing deps
        conn = await tool._get_connection()
    else:
        raise

When it happens

Trigger: The Snowflake packages were absent at __init__ (so _pool_lock was never assigned), and _get_connection is called afterwards; or object state was mutated/cleared externally (e.g. after close/cleanup) while a query is still in flight.

Common situations: Swallowing the ImportError from construction (try/except pass) and then calling the tool; reusing a tool instance after its resources were torn down; partial initialization when the auto-install prompt was declined.

Related errors

• Connection pool not initialized
• An error occurred while running the declarative flow
• Client is not initialized
• Client not initialized
• Either password or private_key_path must be provided

AI-assisted analysis of crewAIInc/crewAI@754d7323be (2026-08-15). Data as JSON: /api/errors/6ac421b7735acf8a. Report an issue: GitHub.

Appendix: source

Thrown at lib/crewai-tools/src/crewai_tools/tools/snowflake_search_tool/snowflake_search_tool.py:163

                        ],
                        check=True,
                    )

                    self._connection_pool = []
                    self._pool_lock = threading.Lock()
                    self._thread_pool = ThreadPoolExecutor(max_workers=self.pool_size)
                except subprocess.CalledProcessError as e:
                    raise ImportError("Failed to install Snowflake dependencies") from e
            else:
                raise ImportError(
                    "Snowflake dependencies not found. Please install them by running "
                    "`uv add cryptography snowflake-connector-python snowflake-sqlalchemy`"
                ) from None

    async def _get_connection(self) -> SnowflakeConnection:
        """Get a connection from the pool or create a new one."""
        if self._pool_lock is None:
            raise RuntimeError("Pool lock not initialized")
        if self._connection_pool is None:
            raise RuntimeError("Connection pool not initialized")
        with self._pool_lock:
            if self._connection_pool:
                return self._connection_pool.pop()
        return await asyncio.get_event_loop().run_in_executor(
            self._thread_pool, self._create_connection
        )

    def _create_connection(self) -> SnowflakeConnection:
        """Create a new Snowflake connection."""
        conn_params: dict[str, Any] = {
            "account": self.config.account,
            "user": self.config.user,
            "warehouse": self.config.warehouse,
            "database": self.config.database,
            "schema": self.config.snowflake_schema,
            "role": self.config.role,

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