fix(environment): keep the package importable without unix sockets

hud/environment/egress.py

@@ -526,14 +526,16 @@ def handle(self) -> None:
             _relay(self.request, upstream)
 
 
-class _UnixServer(socketserver.ThreadingUnixStreamServer):
-    daemon_threads = True
-    request_queue_size = socket.SOMAXCONN
-
-    def get_request(self) -> tuple[socket.socket, tuple[str, int]]:
-        # A unix peer has no address; the handler wants one to log.
-        request, _ = super().get_request()
-        return request, ("workspace", 0)
+if sys.platform != "win32":  # the sockets this serves on have no Windows analogue
+
+    class _UnixServer(socketserver.ThreadingUnixStreamServer):
+        daemon_threads = True
+        request_queue_size = socket.SOMAXCONN
+
+        def get_request(self) -> tuple[socket.socket, tuple[str, int]]:
+            # A unix peer has no address; the handler wants one to log.
+            request, _ = super().get_request()
+            return request, ("workspace", 0)
 
 
 class Egress:

hud/environment/namespace.py

@@ -8,7 +8,6 @@
 import json
 import logging
 import os
-import pty
 import shutil
 import signal
 import socket
@@ -22,6 +21,9 @@
 from hud.environment.utils import splice
 from hud.utils.process import ProcessGroup, ProcessResult, create_process_group_exec
 
+if sys.platform != "win32":  # the pty a session runs on has no Windows analogue
+    import pty
+
 _AF_NETLINK = getattr(socket, "AF_NETLINK", 16)
 _NETLINK_ROUTE = getattr(socket, "NETLINK_ROUTE", 0)
 LOGGER = logging.getLogger("hud.environment.namespace")

hud/environment/tests/test_platform.py

@@ -0,0 +1,52 @@
+"""Regression test for importing the package where unix sockets do not exist.
+
+Both routes out of a workspace are served on unix sockets and a session runs on a pty,
+and each reached for its platform at module scope: a
+``socketserver.ThreadingUnixStreamServer`` subclass in :mod:`hud.environment.egress`,
+and a top-level ``import pty`` in :mod:`hud.environment.namespace`. Neither exists on
+Windows, so ``import hud`` raised there before any of it was used, taking down the
+commands that never go near a workspace with it. Both now sit behind the platform
+guard the rest of the package already applies.
+
+The breakage is at import time, so the check runs in a fresh interpreter. That
+interpreter imports the package once as the platform it really is, because the
+standard library and the dependencies settle their own platform at their first import
+and will not be told otherwise afterwards, and then imports it again with only the
+package's own modules dropped, the platform reported as Windows, and the unix pieces
+taken away.
+"""
+
+from __future__ import annotations
+
+import subprocess
+import sys
+
+_IMPORT_AS_WINDOWS = """
+import socketserver
+import sys
+
+import hud
+
+for name in [n for n in sys.modules if n == "hud" or n.startswith("hud.")]:
+    del sys.modules[name]
+
+sys.platform = "win32"
+sys.modules["pty"] = None  # a Windows interpreter has no pty module to import
+socketserver.__dict__.pop("ThreadingUnixStreamServer", None)  # nor this server
+
+import hud
+
+print("IMPORTED")
+"""
+
+
+def test_the_package_imports_where_unix_sockets_do_not_exist() -> None:
+    result = subprocess.run(
+        [sys.executable, "-c", _IMPORT_AS_WINDOWS],
+        capture_output=True,
+        text=True,
+        timeout=120,
+    )
+
+    assert result.returncode == 0, f"stdout={result.stdout!r}\nstderr={result.stderr!r}"
+    assert "IMPORTED" in result.stdout

hud/environment/tests/test_workspace.py

@@ -30,7 +30,7 @@
 from hud.capabilities import SSHClient
 from hud.environment import namespace as namespace_mod
 from hud.environment import workspace as workspace_mod
-from hud.environment.egress import Peer, _field, _UnixServer, _Unrelayable
+from hud.environment.egress import Peer, _field, _Unrelayable
 from hud.environment.workspace import Bubblewrap, Mount, Workspace
 from hud.utils.process import ProcessGroup, ProcessResult
 
@@ -657,6 +657,8 @@ async def spawn(argv: list[str], **kwargs: Any) -> Any:
 
 
 def test_peer_forwarders_use_the_substrate_listen_backlog() -> None:
+    from hud.environment.egress import _UnixServer  # unix-only, as this module is
+
     assert _UnixServer.request_queue_size == socket.SOMAXCONN