Add analyze-CI-shard-timeout.py script.

This can be used to analyze a CI shard log from a timed out job to see
which tests never finished.

scripts/analyze-CI-shard-timeout.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+
+import os
+import re
+import sys
+from pathlib import Path
+from textwrap import dedent
+from typing import Any
+
+
+def analyze(log: Path) -> Any:
+    tests: dict[str, bool] = {}
+    with log.open() as fp:
+        for line in fp:
+            # E.G.: 2024-11-13T06:29:33.3456360Z tests/integration/test_issue_1018.py::test_execute_module_alter_sys[ep-function-zipapp-VENV]
+            match = re.match(r"^.*\d+Z (?P<test>tests/\S+(?:\[[^\]]+\])?).*", line)
+            if match:
+                test = match.group("test")
+                if test not in tests:
+                    tests[test] = False
+                continue
+
+            # E.G.: 2024-11-13T06:29:33.3478200Z [gw3] PASSED tests/integration/venv_ITs/test_issue_1745.py::test_interpreter_mode_python_options[-c <code>-VENV]
+            match = re.match(r"^.*\d+Z \[gw\d+\] [A-Z]+ (?P<test>tests/\S+(?:\[[^\]]+\])?).*", line)
+            if match:
+                tests[match.group("test")] = True
+                continue
+
+    hung_tests = sorted(test for test, complete in tests.items() if not complete)
+    if hung_tests:
+        return f"The following tests never finished:\n{os.linesep.join(hung_tests)}"
+
+
+def main() -> Any:
+    if len(sys.argv) != 2:
+        return dedent(
+            f"""\
+            Usage: {sys.argv[0]} <CI log file>
+
+            Analyzes a Pex CI log file from a timed-out shard to determine
+            which tests never completed.
+            """
+        )
+
+    log = Path(sys.argv[1])
+    if not log.exists():
+        return f"The log specified at {sys.argv[0]} does not exist."
+
+    return analyze(Path(sys.argv[1]))
+
+
+if __name__ == "__main__":
+    sys.exit(main())