redis/redis-py · critical · NotImplementedError

DEBUG SEGFAULT is intentionally not implemented in the clien

Error message

DEBUG SEGFAULT is intentionally not implemented in the client. For more information, see https://redis.io/commands/debug-segfault

What it means

debug_segfault is a stub that always raises NotImplementedError. DEBUG SEGFAULT intentionally crashes the Redis server process for testing purposes; exposing it as a normal client method would be a severe footgun, so the library refuses to implement it.

Source

Thrown at redis/commands/core.py:1517

    ) -> dict[str, str | int] | bytes | str: ...

    @overload
    def debug_object(
        self: AsyncClientProtocol, key: KeyT, **kwargs
    ) -> Awaitable[dict[str, str | int] | bytes | str]: ...

    def debug_object(self, key: KeyT, **kwargs) -> (
        dict[str, str | int] | bytes | str
    ) | Awaitable[dict[str, str | int] | bytes | str]:
        """
        Returns version specific meta information about a given key

        For more information, see https://redis.io/commands/debug-object
        """
        return self.execute_command("DEBUG OBJECT", key, **kwargs)

    def debug_segfault(self, **kwargs) -> None:
        raise NotImplementedError(
            """
            DEBUG SEGFAULT is intentionally not implemented in the client.

            For more information, see https://redis.io/commands/debug-segfault
            """
        )

    @overload
    def echo(self: SyncClientProtocol, value: EncodableT, **kwargs) -> bytes | str: ...

    @overload
    def echo(
        self: AsyncClientProtocol, value: EncodableT, **kwargs
    ) -> Awaitable[bytes | str]: ...

    def echo(self, value: EncodableT, **kwargs) -> (bytes | str) | Awaitable[
        bytes | str
    ]:

View on GitHub (pinned to da03cdc7e8)

Solutions

Do not call debug_segfault from application code — it would crash the server.
If you genuinely need to test server crashes, use execute_command('DEBUG', 'SEGFAULT') in a disposable test environment.
For safe debug operations, use r.debug_object(key) instead.

Example fix

# before
r.debug_segfault()
# after (only in a throwaway test env)
r.execute_command('DEBUG', 'SEGFAULT')

Defensive patterns

Strategy: validation

Validate before calling

# never call debug_segfault in production code
# remove or guard any code path that reaches it

Prevention

DEBUG SEGFAULT crashes the Redis server — the stub exists to prevent accidental invocation.
Only use it via execute_command in isolated, disposable test environments.

When it happens

Trigger: Calling r.debug_segfault() — always raises. Calling it in a test harness that enumerates all debug_* methods.

Common situations: Developer running chaos/fault-injection tests and reaching for the python method. Copying a crash-reproduction recipe from a blog. Expecting the client to mirror every DEBUG subcommand.

Related errors

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/db5e73fe0ecb3303.json. Report an issue: GitHub.