[Bug]: Disable function calling for DeepSeek

[enyst]

Is there an existing issue for the same bug?

• I have checked the existing issues.

Describe the bug and reproduction steps

Trying to run on the current main with UI. I started a new "project" in the UI. Then I wrote "print 55":

10:13:33 - openhands:DEBUG: stream.py:144 - Adding ErrorObservation id=10 from USER
10:13:33 - openhands:DEBUG: stream.py:144 - Adding AgentStateChangedObservation id=11 from AGENT
10:13:33 - openhands:DEBUG: agent_controller.py:135
OBSERVATION
[Agent Controller dfcf323b-009e-4e0d-af91-126f1fe9ca4f] **ErrorObservation**
There was an unexpected error while running the agent:litellm.BadRequestError: DeepseekException - Failed to deserialize the JSON body into the target type: messages[2]: invalid type: sequence, expected a string at line 1 column 683

DeepSeek supports tool use, but I'm not sure we tested with DeepSeek? We really need that CI eval PR. 😅

Note:

• the first prompt to the LLM was:

You are a helpful assistant that can interact with a computer to solve tasks.
<IMPORTANT>
* If user provides a path, you should NOT assume it's relative to the current working directory. Instead, you should explore the file system to find the file before working on it.
</IMPORTANT>


----------

print 55

• the second prompt was:

You are a helpful assistant that can interact with a computer to solve tasks.
<IMPORTANT>
* If user provides a path, you should NOT assume it's relative to the current working directory. Instead, you should explore the file system to find the file before working on it.
</IMPORTANT>


----------

print 55

----------



----------

OBSERVATION:
echo 55
55[Python Interpreter: /openhands/poetry/openhands-ai-5O4_aCHf-py3.12/bin/python]
openhands@openhands-workspace:/workspace $ 
[Command finished with exit code 0]

OpenHands Installation

Development workflow

OpenHands Version

No response

Operating System

None

Logs, Errors, Screenshots, and Additional Context

No response

[enyst]

We need to disable function calling for DeepSeek.

Function calling is enabled or disabled in the openhands/agenthub/codeact_agent/codeact_agent.py file.

We can define some module global to disable it for any models with 'deepseek'.

[github-actions]

OpenHands started fixing the issue! You can monitor the progress here.

[github-actions]

An attempt was made to automatically fix this issue, but it was unsuccessful. A branch named 'openhands-fix-issue-4604' has been created with the attempted changes. You can view the branch here. Manual intervention may be required.