fix: AdvancedProfiler: ValueError: Attempting to stop recording a

[majiayu000]

Now I have a complete understanding of the changes. Let me generate the PR description:

Fix AdvancedProfiler ValueError when stopping non-started actions

Closes #9136

Summary

The AdvancedProfiler raised a ValueError when attempting to stop profiling an action that was never started. This commonly occurred when using multiple Trainers with a shared profiler instance (e.g., during grid search) where only one trainer runs the test phase. The fix changes the stop() method to gracefully handle this case by logging a debug message and returning early instead of raising an exception.

Changes Made

• src/lightning/pytorch/profilers/advanced.py:

  • Modified the stop() method to log a debug message and return gracefully when attempting to stop an action that was never started, instead of raising ValueError

• tests/tests_pytorch/profilers/test_profiler.py:

  • Added test_advanced_profiler_multiple_trainers_test_only_one: Reproduces the exact bug scenario from issue AdvancedProfiler: ValueError: Attempting to stop recording an action (run_test_evaluation) which was never started. #9136 with multiple trainers sharing a profiler where only one runs test
  • Added test_advanced_profiler_reused_trainer_test: Tests reusing a trainer for multiple test calls with profiling
  • Added test_advanced_profiler_stop_nonexistent_action_no_error: Verifies that stopping non-existent actions doesn't raise errors and the profiler remains functional

Testing

The fix can be verified by:

1. Running the new test cases:

   pytest tests/tests_pytorch/profilers/test_profiler.py::test_advanced_profiler_multiple_trainers_test_only_one
   pytest tests/tests_pytorch/profilers/test_profiler.py::test_advanced_profiler_reused_trainer_test
   pytest tests/tests_pytorch/profilers/test_profiler.py::test_advanced_profiler_stop_nonexistent_action_no_error

2. Running the full profiler test suite:

   pytest tests/tests_pytorch/profilers/test_profiler.py -v

Checklist

• Tests pass locally
• Code follows project style guidelines
• No breaking changes

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📚 Documentation preview 📚: https://pytorch-lightning--21451.org.readthedocs.build/en/21451/