tests: contain security-conftest network block; fix stale mlx paths; skip GPU import in trainer-exec-marker

.github/workflows/consolidated-tests-ci.yml

@@ -207,7 +207,13 @@ jobs:
           set -euxo pipefail
           python -m pip install --upgrade pip
           pip install --index-url https://download.pytorch.org/whl/cpu \
-            "torch>=2.4.0,<2.11.0"
+            "torch>=2.4.0,<2.11.0" "torchvision<0.26"
+          # torchvision: transitive import of transformers.models.qwen2_vl
+          # / qwen2_5_vl image processors. The Qwen2_VL image-processor
+          # zoo references chains through `from torchvision...` at module
+          # top, so a missing torchvision turns the existence-probe drift
+          # tests RED on "ModuleNotFoundError: No module named 'torchvision'".
+          # CPU build is plenty; we don't need the CUDA variant.
           pip install -e .[core]
           pip install --no-deps "unsloth @ git+https://github.com/unslothai/unsloth@main" || true
           # Override with matrix-resolved specs.

tests/security/conftest.py

@@ -1,11 +1,20 @@
 """Shared fixtures for the security regression suite.
 
 The scanner scripts under audit are designed to be offline-safe. Pin
-that invariant by autouse-installing a session-scoped network blocker
+that invariant by autouse-installing a function-scoped network blocker
 that refuses any non-loopback `socket.connect()` from inside the test
 process. If a future test (or a scanner regression) accidentally tries
 to reach the public internet, pytest fails loudly instead of leaking
 the request.
+
+Scope is intentionally ``function`` rather than ``session``: the swap
+mutates a module-global (``socket.socket``), and a session-scoped swap
+keeps the patch live for every test pytest runs after the first
+security test in the same session -- which silently broke every
+network-using test elsewhere in the tree (e.g.
+``tests/test_upstream_pinned_symbols_transformers.py`` which fetches
+HF modeling source over HTTPS). Per-function setup/teardown costs
+~10us and contains the blast radius to security tests only.
 """
 
 from __future__ import annotations
@@ -68,12 +77,15 @@ def connect_ex(self, address):  # type: ignore[override]
         return super().connect_ex(address)
 
 
-@pytest.fixture(scope = "session", autouse = True)
+@pytest.fixture(scope = "function", autouse = True)
 def network_blocker():
-    """Session-scoped fixture; replaces `socket.socket` with a blocker.
+    """Function-scoped fixture; replaces `socket.socket` with a blocker.
 
     Yields nothing; the swap is the side effect. Restored at teardown
-    so other test sessions (run interleaved) see a clean module.
+    so the *next* test (security or otherwise) sees the real socket.
+    Session scope was a footgun: it leaked the patch into every
+    network-using test in the parent ``tests/`` tree once a single
+    security test ran. See the module docstring for the regression.
     """
     original = socket.socket
     socket.socket = _BlockedSocket  # type: ignore[assignment]

tests/test_compiler_rewriter_exhaustive.py

@@ -2033,11 +2033,23 @@ def test_unsloth_rl_peft_pattern_27_marker():
 
 def test_unsloth_trainer_exec_marker():
     """``unsloth/trainer.py:614`` exec()'s synthesized trainer source;
-    pin that unsloth.trainer is importable."""
-    pytest.importorskip("unsloth")
+    pin that unsloth.trainer is importable.
+
+    Skips on a host without a real accelerator: ``import unsloth`` raises
+    ``NotImplementedError("Unsloth cannot find any torch accelerator")``
+    at top-level on a CPU-only CI runner, which is neither an ImportError
+    nor a drift signal -- it's just the harness gate. ``importorskip``
+    only converts ``ImportError`` to ``skip``, so we have to wrap the
+    whole import path. Treat the no-accelerator case as skip so the
+    no-GPU CI cell goes green; the GPU cell still exercises the import
+    end-to-end.
+    """
     try:
+        import unsloth  # noqa: F401
         import unsloth.trainer as trainer_mod
     except ImportError as e:
+        if e.name == "unsloth":
+            pytest.skip(f"unsloth is not installed: {e}")
         _drift(
             "unsloth/trainer.py:614",
             "import unsloth.trainer",
@@ -2046,6 +2058,10 @@ def test_unsloth_trainer_exec_marker():
             "unreachable.",
         )
         return
+    except NotImplementedError as e:
+        if "accelerator" in str(e) or "GPU" in str(e):
+            pytest.skip(f"No accelerator visible to unsloth import: {e}")
+        raise
     # Module must expose some Trainer-family symbol downstream rewriter consumes.
     if not any(
         hasattr(trainer_mod, sym)

tests/test_upstream_pinned_symbols_accelerator.py

@@ -215,17 +215,27 @@ def test_moe_expert_merges_call_active_merge_device():
 # ---------------------------------------------------------------------------
 
 def test_mlx_trainer_uses_modern_memory_apis_only():
-    """unsloth_zoo.mlx_trainer must call the non-namespaced memory APIs
+    """unsloth_zoo.mlx.trainer must call the non-namespaced memory APIs
     (mx.set_memory_limit, mx.set_cache_limit, mx.set_wired_limit). The
     namespaced mx.metal.set_* forms are deprecated upstream and reverting
     to them resurrects the per-run deprecation warning that 70b93ad fixed.
     """
     import importlib.util
     import pathlib
 
-    mlx_trainer_path = pathlib.Path(
+    pkg_root = pathlib.Path(
         importlib.util.find_spec("unsloth_zoo").submodule_search_locations[0]
-    ) / "mlx_trainer.py"
+    )
+    # The MLX path was promoted from a flat module (mlx_trainer.py) to a
+    # subpackage (mlx/trainer.py) in e6d8f7f. Accept either layout so the
+    # test survives the rename.
+    candidates = [pkg_root / "mlx" / "trainer.py", pkg_root / "mlx_trainer.py"]
+    mlx_trainer_path = next((c for c in candidates if c.is_file()), None)
+    assert mlx_trainer_path is not None, (
+        f"Neither {candidates[0]} nor {candidates[1]} exists; the MLX "
+        f"trainer module was relocated again. Update this test's path "
+        f"candidates."
+    )
     src = mlx_trainer_path.read_text()
 
     # The deprecated forms must NOT appear.
@@ -240,7 +250,7 @@ def test_mlx_trainer_uses_modern_memory_apis_only():
 
     # The modern forms must appear.
     for modern in ("mx.set_memory_limit", "mx.set_cache_limit", "mx.set_wired_limit"):
-        assert modern in src, f"Expected modern API {modern} missing from mlx_trainer.py"
+        assert modern in src, f"Expected modern API {modern} missing from {mlx_trainer_path.name}"
 
 
 # ---------------------------------------------------------------------------
@@ -327,10 +337,21 @@ def test_get_existing_mlx_quantization_detects_both_keys():
     """
     # Import the helper without triggering the heavy mlx_loader import
     # chain on the GPU-free harness. We pull the function directly.
+    # Layout was promoted from mlx_loader.py (flat) to mlx/loader.py
+    # (subpackage) in e6d8f7f. Try both so the test survives the rename.
     import importlib.util
     import pathlib
-    pkg_loc = importlib.util.find_spec("unsloth_zoo").submodule_search_locations[0]
-    src = (pathlib.Path(pkg_loc) / "mlx_loader.py").read_text()
+    pkg_loc = pathlib.Path(
+        importlib.util.find_spec("unsloth_zoo").submodule_search_locations[0]
+    )
+    candidates = [pkg_loc / "mlx" / "loader.py", pkg_loc / "mlx_loader.py"]
+    loader_path = next((c for c in candidates if c.is_file()), None)
+    assert loader_path is not None, (
+        f"Neither {candidates[0]} nor {candidates[1]} exists; the MLX "
+        f"loader module was relocated again. Update this test's path "
+        f"candidates."
+    )
+    src = loader_path.read_text()
 
     # The function must check BOTH key names; otherwise repos saved by
     # mlx-lm (key "quantization") OR by HF transformers ("quantization_config")