SelectorGroupChat ignores selector function randomly.

[BenConstable9]

What happened?

I have a multi agent system using selector group chat in v0.4. I have a customer selector functions. I can see from the logs, sometimes it gets called, where as sometimes after an agent invocation, it is not called again.

These agents have tools available to them. I can see from the logs that one agent is stuck in a loop where the group chat manager keeps calling it.

What did you expect to happen?

The selector function is always called after each agent invocation.

How can we reproduce it (as minimally and precisely as possible)?

def text_2_sql_generator_selector_func(messages):
    logging.info("Messages: %s", messages)

termination = TextMentionTermination("TERMINATE") | MaxMessageTermination(10)
generator = SelectorGroupChat(
    [
        QUERY_AGENT,
        REVISE_AGENT,
        TEST_AGENT
    ],
    allow_repeated_speaker=False,
    model_client=<model>,
    termination_condition=termination,
    selector_func=selector_function,
)

AutoGen version

v0.4

Which package was this bug in

AgentChat

Model used

gpt-4o-mini

Python version

No response

Operating system

No response

Any additional info you think would be helpful for fixing this bug

No response

[ekzhu]

@BenConstable9 if the selector function doesn't return a value then the model will be used as a backup.

https://microsoft.github.io/autogen/dev/reference/python/autogen_agentchat/autogen_agentchat.teams.html#autogen_agentchat.teams.SelectorGroupChat

[BenConstable9]

@ekzhu I have this scenario but I can see from the logs that the selector isn't called in the first place.

I am logging the result that the selector returns and from the logs, I can see it isn't always called after each agent.

[ekzhu]

I am sorry but the code you provided the selector function doesn't return a value.

You probably need to debug into the framework a bit if providing code isn't an option.

[BenConstable9]

Closing after discussion internally