Fix server-side transports on Python 3.11/3.12, and report accept-path errors loudly

python/loopmini/loop.py

@@ -180,7 +180,13 @@ def _remove_writer(self, fd): return self.remove_writer(fd)
     sock_connect,_sock_connect,_sock_connect_cb = _SelLoop.sock_connect,_SelLoop._sock_connect,_SelLoop._sock_connect_cb
 
     def _make_socket_transport(self, sock, protocol, waiter=None, *, extra=None, server=None, context=None):
-        return SockTransport(self, sock, protocol, waiter, extra, server, context)
+        # The accept path (gh: _accept_connection2) swallows transport-creation errors
+        # outside debug mode; report before re-raising so server-side bugs are never silent
+        try: return SockTransport(self, sock, protocol, waiter, extra, server, context)
+        except (SystemExit, KeyboardInterrupt): raise
+        except BaseException as e:
+            if server is not None: self.call_exception_handler(dict(message='loopmini: error creating server-side transport', exception=e, socket=sock))
+            raise
 
     def _make_ssl_transport(self, sock, protocol, sslcontext, waiter=None, *, server_side=False, server_hostname=None, extra=None, server=None,
         ssl_handshake_timeout=None, ssl_shutdown_timeout=None, call_connection_made=True, context=None):

python/loopmini/transports.py

@@ -1,5 +1,6 @@
 "Socket transports for the Rust-reactor loop, feeding stock asyncio protocols."
-import asyncio, socket
+import asyncio, socket, sys
+_server_takes_transport = sys.version_info >= (3, 13)  # Server._attach/_detach gained the transport arg in 3.13 (gh-113538)
 from asyncio import constants, futures, transports
 
 class _TransportLifecycle:
@@ -40,7 +41,7 @@ def __init__(self, loop, sock, protocol, waiter=None, extra=None, server=None, c
             except OSError: pass
         self._buffer = bytearray()
         self._closing = self._reading = self._eof = self._lost = False
-        if server is not None: server._attach(self)
+        if server is not None: server._attach(self) if _server_takes_transport else server._attach()
         loop.call_soon(protocol.connection_made, self, context=context)
         loop.call_soon(self.resume_reading, context=context)
         if waiter is not None: loop.call_soon(futures._set_result_unless_cancelled, waiter, None)
@@ -137,7 +138,7 @@ def _force_close(self, exc):
     def _close_resource(self):
         self._sock.close()
         if self._server is not None:
-            self._server._detach(self)
+            self._server._detach(self) if _server_takes_transport else self._server._detach()
             self._server = None
 
 class DatagramTransport(_TransportLifecycle, asyncio.DatagramTransport):

tests/test_loop.py

@@ -2,7 +2,8 @@
 import asyncio, contextvars, ctypes, os, pytest, random, signal, socket, sys, threading, time
 import loopmini
 
-def run(coro): return asyncio.run(coro, loop_factory=loopmini.new_event_loop)
+def run(coro):
+    with asyncio.Runner(loop_factory=loopmini.new_event_loop) as r: return r.run(coro)
 
 def test_cancelled_timer_released():
     """A cancelled timer must leave the reactor's timer map at once.