fix: use spawn context for terraform pool

Author: Prodesire

src/libterraform/pool.py

@@ -222,7 +222,10 @@ def __init__(
         initializer=None,
         initargs: tuple = (),
     ):
-        self._manager = (mp_context or multiprocessing).Manager()
+        if mp_context is None:
+            mp_context = multiprocessing.get_context("spawn")
+
+        self._manager = mp_context.Manager()
         self._cancel_registry = self._manager.dict()
         self._executor = ProcessPoolExecutor(
             max_workers=max_workers,

tests/cli/test_pool.py

@@ -5,6 +5,7 @@
 import pytest
 
 from libterraform import TerraformCommand, TerraformPool
+import libterraform.pool as pool_module
 from libterraform.cli import CommandResult
 from libterraform.exceptions import TerraformCommandError
 from libterraform.pool import PoolCommand
@@ -69,6 +70,47 @@ def test_pool_shutdown_rejects_new_work():
         pool.run("version")
 
 
+def test_pool_defaults_to_spawn_context(monkeypatch):
+    calls = []
+    created = {}
+
+    class FakeManager:
+        def dict(self):
+            return {}
+
+        def shutdown(self):
+            pass
+
+    class FakeContext:
+        def Manager(self):
+            return FakeManager()
+
+    class FakeExecutor:
+        def __init__(self, **kwargs):
+            created.update(kwargs)
+
+        def shutdown(self, wait=True, *, cancel_futures=False):
+            created["shutdown"] = (wait, cancel_futures)
+
+    fake_context = FakeContext()
+
+    def fake_get_context(method):
+        calls.append(method)
+        return fake_context
+
+    monkeypatch.setattr(pool_module.multiprocessing, "get_context", fake_get_context)
+    monkeypatch.setattr(pool_module, "ProcessPoolExecutor", FakeExecutor)
+
+    pool = TerraformPool(max_workers=1)
+    pool.shutdown()
+
+    assert calls == ["spawn"]
+    assert created["max_workers"] == 1
+    assert created["mp_context"] is fake_context
+    assert created["initargs"][0] == {}
+    assert created["shutdown"] == (True, False)
+
+
 def test_pool_command_proxy_exposes_public_sync_methods():
     from libterraform.cli import _STREAM_METHODS