redis/redis-py · error · NotImplementedError

DEBUG SEGFAULT is intentionally not implemented in the…

Error message

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

What it means

Raised by debug_segfault() (redis/commands/core.py:1517) which is a stub that unconditionally raises NotImplementedError. DEBUG SEGFAULT deliberately crashes the Redis server process for testing; shipping it on a client object would be a footgun, so the library refuses it. No arguments are accepted.

Solutions

Do not call debug_segfault() from application code
If you genuinely need to crash a test server, invoke it via redis-cli or r.execute_command("DEBUG", "SEGFAULT") on a throwaway instance only
Use r.debug_object(key) for safe object diagnostics instead

Example fix

# before
r.debug_segfault()
# after
# (remove the call; it is intentionally disabled)
# if absolutely required for a local test instance:
# r.execute_command("DEBUG", "SEGFAULT")

Defensive patterns

Strategy: validation

Validate before calling

# never call debug_segfault(); gate it behind an explicit flag
if not getattr(r, "_allow_segfault", False):
    raise RuntimeError("debug_segfault is disabled")

Try / catch

try:
    r.debug_segfault()
except NotImplementedError:
    if os.environ.get("ALLOW_DEBUG_SEGFAULT") == "1":
        r.execute_command("DEBUG", "SEGFAULT")

Prevention

Remove debug_segfault() calls from application code entirely.
If used for fault injection, restrict to disposable test instances and use redis-cli.
Remember other debug_* methods (debug_object, debug_sleep) are safe and implemented.

When it happens

Trigger: Calling r.debug_segfault() or r.debug_segfault(anything). Any call raises immediately and never contacts the server.

Common situations: Running chaos/fault-injection tests and reaching for the python client; or exploring the DEBUG surface (note debug_object, debug_sleep, etc. ARE implemented, only segfault is blocked).

Related errors

AI-assisted analysis of redis/redis-py@6a6b581b48 (2026-08-10). Data as JSON: /api/errors/db5e73fe0ecb3303. Report an issue: GitHub.

Appendix: 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
    ]:

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