WARNING livekit.plugins.google - no candidates in the response

[ocracy]

Bug Description

Sometimes google return no candidate and fallback mechanisim not working how to fix?

Expected Behavior

If gemini response has no candidate it should fallback to other LLM

Reproduction Steps

it depends google

Operating System

ubuntu

Models Used

gemini 2.5 flash

Package Versions

pendencies = [
    "livekit-agents[anam,bey,bithuman,cartesia,deepgram,mcp,openai,silero,simli,tavus,turn-detector]~=1.2",
    "livekit-plugins-azure>=1.2.6",
    "livekit-plugins-elevenlabs>=1.2.6",
    "livekit-plugins-google>=1.2.6",
    "livekit-plugins-minimax>=1.2.6",
    "livekit-plugins-noise-cancellation~=0.2",
    "livekit-plugins-speechmatics>=1.2.6",
    "pip",
    "python-dotenv>=1.1.1",

Session/Room/Call IDs

No response

Proposed Solution

Additional Context

No response

Screenshots and Recordings

2025-11-20 23:03:28,874 - INFO google_genai.models - AFC remote call 1 is done. "", "pid": 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:28,876 - WARNING livekit.plugins.google - no candidates in the response: sdk_http_response=HttpResponse( headers= ) candidates=[Candidate( content=Content( role='model' ), finish_reason=<FinishReason.STOP: 'STOP'>, index=0 )] create_time=None model_version='gemini-2.5-flash' prompt_feedback=None response_id='EHQfacqzMMShxN8Pmfe4qAE' usage_metadata=GenerateContentResponseUsageMetadata( prompt_token_count=6800, prompt_tokens_details=[ ModalityTokenCount( modality=<MediaModality.TEXT: 'TEXT'>, token_count=6800 ), ], total_token_count=6800 ) automatic_function_calling_history=None parsed=None "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:35,981 - ERROR asyncio - Unclosed client session client_session: <aiohttp.client.ClientSession object at 0x11ba34150> 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:37,655 - DEBUG livekit.agents - received user transcript "user_transcript": "E sen zaten kodu verdin bana.", "language": "tr-TR", "pid": 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:37,726 - INFO google_genai.models - AFC is enabled with max remote calls: 10. 2025-11-20 23:03:38,809 - INFO google_genai.models - AFC remote call 1 is done. "", "pid": 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:38,810 - WARNING livekit.plugins.google - no candidates in the response: sdk_http_response=HttpResponse( headers= ) candidates=[Candidate( content=Content( role='model' ), finish_reason=<FinishReason.STOP: 'STOP'>, index=0 )] create_time=None model_version='gemini-2.5-flash' prompt_feedback=None response_id='GnQfaZGhLMO1nsEPt_650QI' usage_metadata=GenerateContentResponseUsageMetadata( prompt_token_count=6808, prompt_tokens_details=[ ModalityTokenCount( modality=<MediaModality.TEXT: 'TEXT'>, token_count=6808 ), ], total_token_count=6808 ) automatic_function_calling_history=None parsed=None "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:48,290 - DEBUG livekit.agents - received user transcript "user_transcript": "Orada mısınız?", "language": "tr-TR", "pid": 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:48,338 - INFO google_genai.models - AFC is enabled with max remote calls: 10. 2025-11-20 23:03:49,892 - INFO google_genai.models - AFC remote call 1 is done. "", "pid": 1119, "job_id": "AJ_HLh7v4qq5gEh"} 2025-11-20 23:03:49,893 - WARNING livekit.plugins.google - no candidates in the response: sdk_http_response=HttpResponse( headers= ) candidates=[Candidate( content=Content( role='model' ), finish_reason=<FinishReason.STOP: 'STOP'>, index=0 )] create_time=None model_version='gemini-2.5-flash' prompt_feedback=None response_id='JXQfacTEMIqhnsEPhZzZ8AE' usage_metadata=GenerateContentResponseUsageMetadata( prompt_token_count=6813, prompt_tokens_details=[ ModalityTokenCount( modality=<MediaModality.TEXT: 'TEXT'>, token_count=6813 ), ], total_token_count=6813 ) automatic_function_calling_history=None parsed=None "AJ_HLh7v4qq5gEh"}