Fix shutdown deadlock on UDS unlink race

Wrap `os.unlink()` in `close_listener()` with a `FileNotFoundError`
guard — under concurrent pytest sessions the sock-file can already be
reaped. Without this the raise aborts `_serve_ipc_eps`'s finally before
`_shutdown.set()`, deadlocking `wait_for_shutdown()` on
`actor.cancel()`.

Also,
- close each endpoint independently in the finally so one raise doesn't
  strand the rest.
- always signal `_shutdown.set()` regardless of remaining ep count.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

tractor/ipc/_server.py

@@ -1122,20 +1122,32 @@ async def _serve_ipc_eps(
             )
 
     finally:
+        # close every endpoint INDEPENDENTLY: a close raising
+        # mid-iter (e.g. UDS `os.unlink` racing concurrent reap) must
+        # not strand the rest of the eps + must not skip the
+        # `_shutdown.set()` below.
         if eps:
             addr: Address
             ep: Endpoint
-            for addr, ep in server.epsdict().items():
+            for addr, ep in list(server.epsdict().items()):
-                ep.close_listener()
+                try:
-                server._endpoints.remove(ep)
+                    ep.close_listener()
+                except Exception as ep_close_err:
+                    log.exception(
+                        f'Endpoint close raised, continuing teardown\n'
+                        f'  |_{ep!r}\n'
+                        f'  |_{ep_close_err!r}\n'
+                    )
+                finally:
+                    try:
+                        server._endpoints.remove(ep)
+                    except ValueError:
+                        pass
 
-        # actor = _state.current_actor()
+        # always signal "shutdown" so `actor.cancel()` →
-        # if actor.is_arbiter:
+        # `ipc_server.wait_for_shutdown()` doesn't deadlock when an
-        #     import pdbp; pdbp.set_trace()
+        # endpoint close raised above.
-
+        if server._shutdown is not None:
-        # signal the server is "shutdown"/"terminated"
-        # since no more active endpoints are active.
-        if not server._endpoints:
             server._shutdown.set()
 
 @acm

tractor/ipc/_uds.py

@@ -344,7 +344,18 @@ def close_listener(
 
     '''
     lstnr.socket.close()
-    os.unlink(addr.sockpath)
+    # tolerate the sock-file being already gone — under concurrent
+    # pytest sessions sharing the bindspace dir, another session's
+    # reap path can unlink it first; raising here aborts the
+    # `_serve_ipc_eps` finally before `_shutdown.set()`, deadlocking
+    # `wait_for_shutdown()` on `actor.cancel()`.
+    try:
+        os.unlink(addr.sockpath)
+    except FileNotFoundError:
+        log.warning(
+            f'UDS sock-file already unlinked, skipping\n'
+            f'  |_{addr.sockpath}\n'
+        )
 
 
 async def open_unix_socket_w_passcred(