pytest start/stop tracer - when needing to figure out which tests didn't finish

conftest.py

# conftest.py
# to run:
# TRACE_START_STOP=1 pytest tests/test_trainer.py
import pytest
import os
trace = os.environ.get('TRACE_START_STOP', "")
@pytest.hookimpl(tryfirst=True, hookwrapper=True)
def pytest_runtest_makereport(item, call):
    outcome = yield
    res = outcome.get_result()
    file_name, _, test_name = res.location
    test = f"{file_name} {test_name}"
    if res.when == "setup" and res.passed:
        if len(trace):
            print(f"\nTRACE {test} start")
    elif res.when == "call" and not res.passed:
        pass
    elif res.when == "teardown":
        if len(trace):
            print(f"\nTRACE {test} stop")