Function xfail_on_expected_exceptions

tests/utils.py:179–205

Turn a NotEnoughInformation exception for the HEAP method into an XFAIL. The HEAP method is known to be flaky in some cases: - In Python 3.10 and earlier with the default glibc malloc, a PyThreadState should exist on the heap that points to the interpreter state.

(
    method: StackMethod,
)

@contextlib.contextmanager
def xfail_on_expected_exceptions(
    method: StackMethod,
) -> Generator[None, None, None]:
    """Turn a NotEnoughInformation exception for the HEAP method into an XFAIL.

    The HEAP method is known to be flaky in some cases:

        - In Python 3.10 and earlier with the default glibc malloc,
          a PyThreadState should exist on the heap that points to the
          interpreter state.
        - For Python 3.11 and later, the PyThreadState for the main thread is
          statically allocated, so we would find a useful PyThreadState on the
          heap only for multithreaded programs.
        - For musl libc, its "mallocng" malloc uses the brk heap only for
          metadata, and always puts user data on anonymous mappings, so we'd
          never find a useful PyThreadstate on the heap segment.

    We want to keep running tests for the HEAP method to ensure it doesn't
    break in unexpected ways, but we'll just imperatively xfail if we see the
    failure condition that we know can happen.
    """
    try:
        yield
    except NotEnoughInformation:  # pragma: no cover
        if method == StackMethod.HEAP:
            pytest.xfail("Could not find interpreter state on brk heap")
        raise


def python_has_inlined_eval_frames(major: int, minor: int) -> bool: