The prior round gated UDS in four modules but `import tractor`
still crashed on Windows: `tractor.ipc._uds` does `from socket
import AF_UNIX` at module top, and several modules in the import
graph (`discovery._api`, `spawn._reap`, `discovery._multiaddr`,
`_testing.addr`) import `_uds` unconditionally. Instead of
guarding every importer, fix the root and collapse the per-module
probes to one capability flag.
- in `ipc/_uds.py`, guard the lone `AF_UNIX` import so the module
stays importable everywhere; expose `HAS_UDS = trio.has_unix`
as the single source of truth (the same predicate that gates
`trio.open_unix_socket()`).
- `ipc/_types.py`, `discovery/_addr.py` and `ipc/_server.py` now
import `UDSAddress`/`MsgpackUDSStream`/`HAS_UDS` directly and
gate the transport + address registries on `HAS_UDS`; drop the
duplicated `getattr(socket,'AF_UNIX')` / `platform.system()`
probes, the dead `HAS_AF_UNIX` conjunct, and the import-time
`log.warning()` spam.
- `devx/_stackscope.py` `enable_stack_on_sig()` early-returns
when `sig is None`, so a missing `SIGUSR1` (Windows) degrades
to a no-op instead of a `TypeError` from `getsignal()` /
`signal()`.
- add a `windows-latest` CI leg (UDS excluded; informational via
`continue-on-error` while support matures) plus an `import
tractor` smoke step as the hard signal for the import fix.
Because `_uds` is importable everywhere `UDSAddress` stays a real
class, so `isinstance()` checks and `wrap_address()` no longer
`AttributeError` on no-UDS hosts; actual socket use stays gated
on `has_unix`.
Review: https://github.com/goodboy/tractor/pull/475
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Gud Boi
83d45435bf