fix(v1.4.1): pristine validation imports + smoke-test preflight

bindings/python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "amplifier-core-py"
-version = "1.4.0"
+version = "1.4.1"
 edition = "2021"
 description = "PyO3 bridge for amplifier-core Rust kernel"
 license = "MIT"

context/release-mandate.md

@@ -165,3 +165,4 @@ there is no fast local rollback — users must wait for a fix.
 | v1.2.3 | 2026-03-16 | `session_state` crash — missing dict field on RustCoordinator | CLI startup crashed | Yanked |
 | v1.2.4 | 2026-03-16 | `_tool_dispatch_context` crash — RustCoordinator lacked `__dict__` | All tool dispatch crashed | Yanked |
 | v1.2.4 | 2026-03-16 | Version files not bumped before tagging | PyPI publish rejected (400) | Re-tagged |
+| v1.4.0 | 2026-04-25 | Validator imports leaked pytest as a runtime dep — `validation/structural/__init__.py` eagerly loaded test base classes whose top-level `import pytest` is undeclared in `pyproject.toml`. The 5 type validators imported `check_on_session_ready` from `.structural` (not `.base`), so a clean `pip install amplifier-core` failed `amplifier` startup with `ModuleNotFoundError: No module named 'pytest'`. The smoke test missed it because the pre-existing CLI install (Step 4) pulled pytest as a transitive dep, masking the missing runtime declaration. | All clean-env users hit ImportError at session init | Yanked. Hot-fix in v1.4.1: moved `check_on_session_ready` to `validation/base.py`, updated 5 validator imports, added pristine-import regression test (subprocess + `sys.modules` poisoning) and pristine-import preflight (Step 1b) in `e2e-smoke-test.sh` that imports the wheel into a bare `python:3.12-slim` before any deps pollute the env. |

crates/amplifier-core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "amplifier-core"
-version = "1.4.0"
+version = "1.4.1"
 edition = "2021"
 description = "Pure Rust kernel for the Amplifier modular AI agent system"
 license = "MIT"

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "amplifier-core"
-version = "1.4.0"
+version = "1.4.1"
 description = "Rust kernel with Python bindings for the Amplifier modular AI agent framework"
 license = "MIT"
 readme = "README.md"

python/amplifier_core/validation/base.py

@@ -1,11 +1,20 @@
 """
 Base types for module validation.
 
-Provides ValidationCheck and ValidationResult dataclasses used by all validators.
+Provides ValidationCheck and ValidationResult dataclasses used by all validators,
+plus structural-check helper functions that operate on imported module objects
+without depending on the test-class hierarchy in ``validation.structural``.
+
+NOTE: ``check_on_session_ready`` lives here (not in ``validation.structural``)
+so the per-type validators can import it without pulling in the pytest-dependent
+test base classes at module-load time. See incident #5 in
+``context/release-mandate.md`` for the v1.4.0 regression that motivated this.
 """
 
+import inspect
 from dataclasses import dataclass
 from dataclasses import field
+from typing import Any
 from typing import Literal
 
 
@@ -51,3 +60,69 @@ def summary(self) -> str:
         passed_count = sum(1 for c in self.checks if c.passed)
         status = "PASSED" if self.passed else "FAILED"
         return f"{status}: {passed_count}/{len(self.checks)} checks passed ({len(self.errors)} errors, {len(self.warnings)} warnings)"
+
+
+def check_on_session_ready(module: Any) -> ValidationCheck | None:
+    """Check whether a module's on_session_ready() function, if present, is valid.
+
+    Validates:
+    1. Presence: returns None when on_session_ready is absent (no check needed).
+    2. Async: returns a failing ValidationCheck when on_session_ready exists but
+       is not async (must be ``async def``).
+    3. Arity (B5): returns a failing ValidationCheck when on_session_ready exists,
+       is async, but accepts no positional arguments — the coordinator argument
+       is required.
+
+    Args:
+        module: The imported module object to inspect.
+
+    Returns:
+        None if no issue found, or a ValidationCheck with passed=False describing
+        the first problem encountered.
+
+    Note:
+        This function lives in ``validation.base`` (not ``validation.structural``)
+        so that the per-type validators can import it without triggering the
+        pytest-dependent test base classes in ``validation.structural``. See
+        incident #5 in ``context/release-mandate.md`` for the v1.4.0 regression
+        that motivated this placement.
+    """
+    fn = getattr(module, "on_session_ready", None)
+    if fn is None:
+        return None
+    if not inspect.iscoroutinefunction(fn):
+        return ValidationCheck(
+            name="on_session_ready_async",
+            passed=False,
+            message=(
+                "on_session_ready() must be async: found sync function. "
+                "Use 'async def on_session_ready(coordinator) -> None:'"
+            ),
+            severity="error",
+        )
+    # B5 fix: validate arity — must accept at least one positional arg (coordinator)
+    try:
+        sig = inspect.signature(fn)
+        positional_params = [
+            p
+            for p in sig.parameters.values()
+            if p.kind
+            in (
+                inspect.Parameter.POSITIONAL_OR_KEYWORD,
+                inspect.Parameter.POSITIONAL_ONLY,
+            )
+            and p.default is inspect.Parameter.empty
+        ]
+        if len(positional_params) < 1:
+            return ValidationCheck(
+                name="on_session_ready_async",
+                passed=False,
+                message=(
+                    "on_session_ready() must accept a coordinator argument: "
+                    "async def on_session_ready(coordinator) -> None"
+                ),
+                severity="error",
+            )
+    except (ValueError, TypeError):
+        pass  # Can't inspect — let it pass; runtime will catch it
+    return None

python/amplifier_core/validation/context.py

@@ -15,7 +15,7 @@
 
 from .base import ValidationCheck
 from .base import ValidationResult
-from .structural import check_on_session_ready
+from .base import check_on_session_ready
 
 
 def _implements_context_manager_interface(obj: Any) -> bool:

python/amplifier_core/validation/hook.py

@@ -15,7 +15,7 @@
 
 from .base import ValidationCheck
 from .base import ValidationResult
-from .structural import check_on_session_ready
+from .base import check_on_session_ready
 
 
 def _implements_hook_handler_interface(obj: Any) -> bool:

python/amplifier_core/validation/orchestrator.py

@@ -15,7 +15,7 @@
 
 from .base import ValidationCheck
 from .base import ValidationResult
-from .structural import check_on_session_ready
+from .base import check_on_session_ready
 
 
 def _implements_orchestrator_interface(obj: Any) -> bool:

python/amplifier_core/validation/provider.py

@@ -16,7 +16,7 @@
 from ..models import ProviderInfo
 from .base import ValidationCheck
 from .base import ValidationResult
-from .structural import check_on_session_ready
+from .base import check_on_session_ready
 
 
 def _implements_provider_interface(obj: Any) -> bool:

python/amplifier_core/validation/structural/__init__.py

@@ -30,10 +30,12 @@ class TestMyToolStructural(ToolStructuralTests):
     - No duplication: Modules just inherit, no copy-paste
 """
 
-import inspect
-from typing import Any
-
-from ..base import ValidationCheck
+# Re-export ``check_on_session_ready`` from ``validation.base`` for backward
+# compatibility. The function lives in ``base`` (not here) so that the per-type
+# validators can import it without triggering the pytest-dependent test base
+# classes below. See incident #5 in ``context/release-mandate.md`` for the
+# v1.4.0 regression that motivated this placement.
+from ..base import check_on_session_ready
 from .test_context import ContextStructuralTests
 from .test_hook import HookStructuralTests
 from .test_orchestrator import OrchestratorStructuralTests
@@ -48,62 +50,3 @@ class TestMyToolStructural(ToolStructuralTests):
     "ContextStructuralTests",
     "check_on_session_ready",
 ]
-
-
-def check_on_session_ready(module: Any) -> ValidationCheck | None:
-    """Check whether a module's on_session_ready() function, if present, is valid.
-
-    Validates:
-    1. Presence: returns None when on_session_ready is absent (no check needed).
-    2. Async: returns a failing ValidationCheck when on_session_ready exists but
-       is not async (must be ``async def``).
-    3. Arity (B5): returns a failing ValidationCheck when on_session_ready exists,
-       is async, but accepts no positional arguments — the coordinator argument
-       is required.
-
-    Args:
-        module: The imported module object to inspect.
-
-    Returns:
-        None if no issue found, or a ValidationCheck with passed=False describing
-        the first problem encountered.
-    """
-    fn = getattr(module, "on_session_ready", None)
-    if fn is None:
-        return None
-    if not inspect.iscoroutinefunction(fn):
-        return ValidationCheck(
-            name="on_session_ready_async",
-            passed=False,
-            message=(
-                "on_session_ready() must be async: found sync function. "
-                "Use 'async def on_session_ready(coordinator) -> None:'"
-            ),
-            severity="error",
-        )
-    # B5 fix: validate arity — must accept at least one positional arg (coordinator)
-    try:
-        sig = inspect.signature(fn)
-        positional_params = [
-            p
-            for p in sig.parameters.values()
-            if p.kind
-            in (
-                inspect.Parameter.POSITIONAL_OR_KEYWORD,
-                inspect.Parameter.POSITIONAL_ONLY,
-            )
-            and p.default is inspect.Parameter.empty
-        ]
-        if len(positional_params) < 1:
-            return ValidationCheck(
-                name="on_session_ready_async",
-                passed=False,
-                message=(
-                    "on_session_ready() must accept a coordinator argument: "
-                    "async def on_session_ready(coordinator) -> None"
-                ),
-                severity="error",
-            )
-    except (ValueError, TypeError):
-        pass  # Can't inspect — let it pass; runtime will catch it
-    return None

python/amplifier_core/validation/tool.py

@@ -15,7 +15,7 @@
 
 from .base import ValidationCheck
 from .base import ValidationResult
-from .structural import check_on_session_ready
+from .base import check_on_session_ready
 
 
 def _implements_tool_interface(obj: Any) -> bool:

scripts/e2e-smoke-test.sh

@@ -126,6 +126,49 @@ WHEEL=$(ls "$WHEEL_DIR"/amplifier_core-*.whl 2>/dev/null | head -1)
 [[ -z "$WHEEL" ]] && fail "No wheel found in $WHEEL_DIR/ — run without --skip-build first"
 log "Using wheel: $(basename "$WHEEL")"
 
+# ---------------------------------------------------------------------------
+# Step 1b: Pristine-import preflight
+# ---------------------------------------------------------------------------
+# Catch the v1.4.0 class of bug: wheel requires a runtime dep not declared in
+# pyproject.toml, but masked by transitive deps in the polluted CLI install
+# environment from Steps 4–5. We install ONLY the wheel into a fresh
+# python:3.12-slim image and verify the production import paths succeed.
+#
+# Required because Step 4's `uv tool install git+microsoft/amplifier@main`
+# pulls a full dep closure (including pytest as a transitive) which can hide
+# missing runtime deps. A clean end-user `pip install amplifier-core` doesn't
+# get that pollution and would fail.
+#
+# See context/release-mandate.md Incident History #5 (v1.4.0 yank).
+
+log "Pristine-import preflight: wheel must import on bare python:3.12-slim..."
+WHEEL_BASENAME="$(basename "$WHEEL")"
+docker run --rm \
+    -v "$WHEEL":"/tmp/${WHEEL_BASENAME}":ro \
+    -e WHEEL_BASENAME="$WHEEL_BASENAME" \
+    python:3.12-slim \
+    bash -c '
+        set -e
+        pip install -q "/tmp/${WHEEL_BASENAME}"
+        python -c "
+import sys
+# Defensive: poison pytest so any leak is detected even on images that happen to ship it
+sys.modules[\"pytest\"] = None
+from amplifier_core.validation import (
+    HookValidator, ToolValidator, OrchestratorValidator,
+    ProviderValidator, ContextValidator,
+)
+from amplifier_core.validation.base import check_on_session_ready
+import amplifier_core._session_init   # noqa: F401
+import amplifier_core.loader          # noqa: F401
+import amplifier_core.coordinator     # noqa: F401
+import amplifier_core.hooks           # noqa: F401
+print(\"pristine import OK\")
+"
+    ' || fail "Pristine-import preflight failed — wheel has runtime dep not declared in pyproject.toml"
+
+log "Pristine-import preflight passed."
+
 # ---------------------------------------------------------------------------
 # Step 2: Create container
 # ---------------------------------------------------------------------------