[Bug]: RetrieveUserProxyAgent ignores customized_prompt

[PyroGenesis]

Describe the bug

RetrieveUserProxyAgent is not making use of customized_prompt

Steps to reproduce

1. Create a RetrieveUserProxyAgent with a customized_prompt in its retrieve_config
2. Start a chat using a_initiate_chat() with an AssistantAgent

Expected Behavior

The AssistantAgent should receive the customized prompt but it doesn't.

Screenshots and logs

No response

Additional Information

AutoGen: v0.2.14
OS: Windows 10
Python: 3.10.11

We narrowed it down to a_initiate_chat() calling a_generate_init_message() which is not implemented for RetrieveUserProxyAgent so it ends up falling back to ConversableAgent.a_generate_init_message() which does not make use of customized_prompt

[gagb]

@thinkall

[thinkall]

Hi @PyroGenesis , I see you've found the root cause. RetrieveUserProxyAgent doesn't support async calls yet. It's on our roadmap. #1657

[PyroGenesis]

Since the introduction of callable messages, this issue can be resolved by using the message_generator callable provided within RetrieveUserProxyAgent

await retrieve_user_proxy_agent.a_initiate_chat(
    general_assistant, 
    message=retrieve_user_proxy_agent.message_generator, 
    problem=problem, 
    n_results=10
)

This still falls back to ConversableAgent.a_generate_init_message() but that's fine because that triggers message_generator as a Callable which returns a message with the customized_prompt and the vector db context.