try to fix windows

runtimepy/net/tcp/connection.py

@@ -219,6 +219,7 @@ async def create_pair(
         peer: type[V] = None,
         serve_kwargs: dict[str, _Any] = None,
         connect_kwargs: dict[str, _Any] = None,
+        host: str = "127.0.0.1",
     ) -> _AsyncIterator[tuple[V, T]]:
         """Create a connection pair."""
 
@@ -241,16 +242,22 @@ def callback(conn: V) -> None:
                 serve_kwargs = {}
 
             server = await stack.enter_async_context(
-                peer.serve(callback, port=0, backlog=1, **serve_kwargs)
+                peer.serve(
+                    callback,
+                    host=host,
+                    port=0,
+                    backlog=1,
+                    **serve_kwargs,
+                )
             )
 
-            host = server.sockets[0].getsockname()
-
             if connect_kwargs is None:
                 connect_kwargs = {}
 
             client = await cls.create_connection(
-                host=host[0], port=host[1], **connect_kwargs
+                host=host,
+                port=server.sockets[0].getsockname()[1],
+                **connect_kwargs,
             )
             await cond.acquire()
 

tests/net/tcp/test_np_05b.py

@@ -144,7 +144,9 @@ async def test_conns(client: Np05bConnection, _: MockNp05b) -> None:
             # End the test.
             stop_sig.set()
 
-    async with MockNp05b.serve(callback=conn_cb, port=0) as server:
+    async with MockNp05b.serve(
+        callback=conn_cb, host="127.0.0.1", port=0
+    ) as server:
         host = sockname(server.sockets[0])
         conn = await Np05bConnection.create_connection(
             host=host.name, port=host.port