Fix grpclib-ttrpc AF_UNIX socket path too long error in Nix builds

Use /tmp for socket paths instead of pytest's tmp_path fixture, which becomes
very long in Nix store context and exceeds the 108-byte Unix socket path limit.

Changes:
- test_functional.py: unix_server fixture uses /tmp/ttrpc_test_{pid}.sock
- conftest.py: socket_path fixture uses /tmp/ttrpc_{pid}.sock with cleanup
- Both fixtures use PID-based unique names to avoid socket collisions
- Added proper cleanup logic to remove stale socket files

All tests now pass in Nix build context.

Author: Lillecarl

pkgs/grpclib-ttrpc/tests/conftest.py

@@ -6,7 +6,7 @@
 import os
 import sys
 from pathlib import Path
-from typing import AsyncGenerator
+from typing import AsyncGenerator, Generator
 
 import pytest
 import pytest_asyncio
@@ -32,9 +32,26 @@ def test_server_bin() -> Path:
 
 
 @pytest.fixture
-def socket_path(tmp_path: Path) -> Path:
-    """Create a unique socket path for each test."""
-    return tmp_path / "ttrpc.sock"
+def socket_path() -> Generator[Path, None, None]:
+    """Create a unique socket path for each test.
+
+    Uses /tmp to avoid "AF_UNIX path too long" error when running in Nix build
+    (pytest's tmp_path is too deep in the Nix store, exceeding 108-byte limit).
+    """
+    path = Path(f"/tmp/ttrpc_{os.getpid()}.sock")
+    # Clean up any stale socket file from previous runs
+    try:
+        if path.exists():
+            path.unlink()
+    except OSError:
+        pass
+    yield path
+    # Clean up after the test
+    try:
+        if path.exists():
+            path.unlink()
+    except OSError:
+        pass
 
 
 @pytest_asyncio.fixture

pkgs/grpclib-ttrpc/tests/test_functional.py

@@ -1,6 +1,7 @@
 """End-to-end functional tests for grpclib_ttrpc.Server."""
 
 import asyncio
+import os
 from typing import cast
 
 import pytest
@@ -56,8 +57,10 @@ async def tcp_client(tcp_server):
 
 
 @pytest_asyncio.fixture
-async def unix_server(tmp_path):
-    sock_path = str(tmp_path / "ttrpc_test.sock")
+async def unix_server():
+    # Use /tmp to avoid "AF_UNIX path too long" error when running in Nix build
+    # (pytest's tmp_path is too deep in the Nix store, exceeding 108-byte limit)
+    sock_path = f"/tmp/ttrpc_test_{os.getpid()}.sock"
     svc = DummyServiceImpl()
     server = Server([svc])
     await server.start(path=sock_path)