`tests/test_ringbuf.py` imports `tractor.ipc._ringbuf` at module
top, which pulls in `tractor.ipc._linux` whose module-level
`ffi.dlopen(None)` raises `OSError` on Windows (and any non-linux
host). That fires at COLLECTION, before the module's existing
`pytestmark = pytest.mark.skip` can apply, so it aborts the whole
pytest session — the new `windows-latest` CI leg never gets past
collection.
- guard the module with `pytest.skip(allow_module_level=True)`
gated on `platform.system() != 'Linux'`, placed before the
crashing import — same idiom as `tests/devx/test_debugger.py`.
- the `eventfd`-based ringbuf backend is linux-only by design, so
macOS skips cleanly too (previously it only skipped incidentally
via the absent `cffi` optional dep).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
f22bfdd282