UDS tpt backend breaks windows on import..

[goodboy]

Apparently us linux heads totally forgot (specifically in #375) that windows doesn't have (obvious) support for unix-domain-sockets, though TIL apparently there is/has-been support ?? (for a long time)

To start we likely just want to fix the immediate crash-on-import

Bp

So for that we should prolly do all of,

• [ ] make sure we aren't always importing the .ipc._uds module by guarding the current ip._types sub-import with a platform check so that by default we're only loading it for supported OSes..
• [ ] maybe log.warning()-explain when we're unable to use that backend and/or require further special dependencies/sys-config to do so (see below) ??
• [ ] write a test which checks if we're running on windows that can at least run in CI
  • presuming we get it running again per #327 and any @no_windows skip-mark usage throughout.

---

On the topic of UDS support in the windows kernel, this blog post claims support was added "Beginning in Insider Build 17063"..

That build page further states,

Unix style sockets (AF_UNIX) are available on Windows AF_UNIX is an address family which has enabled inter-process communication on Unix for countless years. The windows equivalent is named pipes, which offers similar facilities. Based on user feedback, we heard that you’d like an easier path when porting tools relying on AF_UNIX to Windows. As a result, two Win32 processes can now use the AF_UNIX address family over Winsock API to communicate with each other. Read this blog for more details.

and the blog post claims and/or links these further resources:

• only TCP-like "reliable" use is supported per,

  Currently, the support only exists for the stream (SOCK_STREAM) socket type, which is a connection-oriented protocol for one-to-one communication. Support for the datagram (SOCK_DGRAM) can be considered in future depending on the adoption, feedback and scenarios.

  • we [are already using this type] afaik, so we-should-be-gud?

• cpython has for a long while talked support, but it's been super slow moving..
  • longstanding feat-req: https://github.com/python/cpython/issues/77589
    • 2024 summary comment is https://github.com/python/cpython/issues/77589#issuecomment-1963245972
    • latest necro-bump from 2025 is https://github.com/python/cpython/issues/77589#issuecomment-2834722114
  • recent WIP patch => https://github.com/python/cpython/pull/137420
    • latest request for review: https://github.com/python/cpython/pull/137420#issuecomment-3175435577

• the specific section/steps (from that post) on how-to write an AF_UNIX app
• the winsock API docs
• some winsock GH exs (but it doesn't seem to have any examples for AF_UNIX in particular ??)