Fixes#3873
This commit addresses a bug where internal ReAct-style fields like 'Thought:',
'Action:', 'Action Input:', and 'Observation:' were leaking into the final
agent output, particularly in hierarchical crews when delegated tasks failed
or when agents hit max iterations.
Changes:
- Added sanitize_react_output() utility function to strip internal ReAct fields
- Applied sanitization in handle_max_iterations_exceeded() when converting
AgentAction to AgentFinish
- Applied sanitization in format_answer() exception handling to prevent leaks
when LLM responses cannot be parsed
- Added comprehensive unit tests to verify the fix and prevent regressions
- Updated pyproject.toml to use pytest-vcr instead of pytest-recording to
resolve plugin conflicts
The sanitization function removes lines starting with ReAct field markers
while preserving legitimate content, ensuring clean user-facing outputs.
Co-Authored-By: João <joao@crewai.com>
