fix(ci_visibility): set up Test Optimization logging before pytest log capture [backport 3.1]

ddtrace/contrib/internal/pytest/_plugin_v2.py

@@ -181,7 +181,18 @@ def _disable_ci_visibility():
         log.debug("encountered error during disable_ci_visibility", exc_info=True)
 
 
+@pytest.hookimpl(tryfirst=True, hookwrapper=True)
 def pytest_load_initial_conftests(early_config, parser, args):
+    """Perform early initialization of the Test Optimization plugin.
+
+    This has to happen early enough that `sys.stderr` has not been redirected by pytest, so that logging is configured
+    properly. Setting the hook with `tryfirst=True` and `hookwrapper=True` achieves that.
+    """
+    _pytest_load_initial_conftests_pre_yield(early_config, parser, args)
+    yield
+
+
+def _pytest_load_initial_conftests_pre_yield(early_config, parser, args):
     """Performs the bare-minimum to determine whether or ModuleCodeCollector should be enabled
 
     ModuleCodeCollector has a tangible impact on the time it takes to load modules, so it should only be installed if

ddtrace/internal/ci_visibility/utils.py

@@ -117,7 +117,7 @@ def take_over_logger_stream_handler(remove_ddtrace_stream_handlers=True):
     if remove_ddtrace_stream_handlers:
         log.debug("CIVisibility removing DDTrace logger handler")
         ddtrace_logger = logging.getLogger("ddtrace")
-        for handler in ddtrace_logger.handlers:
+        for handler in list(ddtrace_logger.handlers):
             ddtrace_logger.removeHandler(handler)
     else:
         log.warning("Keeping DDTrace logger handler, double logging is likely")

releasenotes/notes/ci_visibility-fix-io-operation-closed-file-1e1089eabd5296ce.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    CI Visibility: This fix resolves an issue where an ``I/O operation on closed file`` error was raised while printing
+    ``ddtrace`` logs during a pytest session, due to a conflict with pytest's log capture.