Fix Qiskit stage plugins and release 0.1.2

.github/workflows/nightly.yml

@@ -1,5 +1,8 @@
 name: Nightly SDK Breakage Detection
 
+# Installs the newest releases of every dependency and fails visibly when the
+# install, dependency resolution or tests break. Do not add continue-on-error,
+# "|| true" or "|| echo" here: a red nightly run is the signal.
 on:
   schedule:
     - cron: "0 2 * * *"
@@ -9,27 +12,22 @@ jobs:
   nightly:
     name: Test against latest SDK versions
     runs-on: ubuntu-latest
-    continue-on-error: true
     steps:
       - uses: actions/checkout@v4
-      - name: Checkout WestQuant Core
+      - name: Checkout WestQuant Core main
         uses: actions/checkout@v4
         with:
           repository: WestQuantOpen/westquant-core
           path: _westquant-core
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
-      - name: Install latest SDKs
+          python-version: "3.12"
+      - name: Install latest dependencies
         run: |
-          pip install --upgrade pip
-          pip install -e ./_westquant-core[test]
-          pip install --upgrade qiskit pytket pennylane pulser 2>/dev/null || true
-          pip install -e .[test] 2>/dev/null || pip install -e .
+          python -m pip install --upgrade pip
+          pip install -e ./_westquant-core
+          pip install --upgrade --upgrade-strategy eager -e ".[test]"
+          pip check
+          pip freeze
       - name: Run tests
-        run: |
-          pytest tests/ -v || echo "Nightly tests failed — SDK breakage detected"
-      - name: Report status
-        if: always()
-        run: |
-          echo "Nightly run completed. Check for SDK breakage above."
+        run: pytest tests/ -v

.github/workflows/publish.yml

@@ -1,34 +1,55 @@
 name: Publish to PyPI
 
+# Single publication path. PyPI Trusted Publishing is bound to this file name
+# (publish.yml) and the "pypi" environment. Tests must pass and the release tag
+# must match the pyproject version before anything is uploaded.
 on:
   release:
     types: [published]
   workflow_dispatch:
-    inputs:
-      confirm:
-        description: 'Type "publish" to confirm'
-        required: true
-        default: 'publish'
+
+permissions:
+  contents: read
 
 jobs:
-  publish:
-    name: Build and publish
+  test:
+    uses: ./.github/workflows/tests.yml
+
+  build:
+    needs: test
     runs-on: ubuntu-latest
-    environment: pypi
-    permissions:
-      id-token: write
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
-          python-version: "3.10"
-      - name: Build package
+          python-version: "3.12"
+      - name: Check release tag matches package version
+        if: github.event_name == 'release'
         run: |
-          pip install build
-          python -m build
-      - name: Check package
+          version=$(python -c "import tomllib; print(tomllib.load(open('pyproject.toml', 'rb'))['project']['version'])")
+          if [ "${GITHUB_REF_NAME#v}" != "$version" ]; then
+            echo "::error::Release tag $GITHUB_REF_NAME does not match pyproject version $version"
+            exit 1
+          fi
+      - name: Build and check distributions
         run: |
-          pip install twine
-          twine check dist/*
-      - name: Publish to PyPI
-        uses: pypa/gh-action-pypi-publish@release/v1
+          python -m pip install --upgrade build twine
+          python -m build
+          twine check --strict dist/*
+      - uses: actions/upload-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+
+  publish:
+    needs: build
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+      - uses: pypa/gh-action-pypi-publish@release/v1

.github/workflows/tests.yml

@@ -1,6 +1,7 @@
 name: Tests
 
 on:
+  workflow_call:
   push:
     branches: [main]
   pull_request:
@@ -12,6 +13,7 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.10", "3.11", "3.12"]
+        qiskit-version: ["2.5.2", "2.6.1"]
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python
@@ -20,8 +22,8 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install
         run: |
-          pip install westquant-core>=0.2.0a1
-          pip install "qiskit~=2.5.2"
+          pip install "westquant-core>=0.2.0a1"
+          pip install "qiskit==${{ matrix.qiskit-version }}"
           pip install -e .[test]
       - name: Test
         run: pytest tests/ -v

CHANGELOG.md

@@ -0,0 +1,25 @@
+# Changelog
+
+## 0.1.2
+
+- Fix: the `westquant` layout, routing and optimization stage plugins crashed
+  on Qiskit 2.x (`QuantumCircuit.from_instructions(dag)` with a `DAGCircuit`)
+  and the candidate path read a private `tqc._layout.dag` attribute. The stages
+  are reimplemented as best-of selections over Qiskit built-in strategies that
+  set `layout` / `final_layout` correctly and use Qiskit's standard embed and
+  routing stage wrappers.
+- Candidate results, including failures, are recorded in
+  `property_set["westquant_selection"]` and failures are logged; if every
+  candidate fails a `TranspilerError` is raised instead of silently returning
+  the input.
+- `optimization_level=0` is no longer replaced by 2 inside the plugin.
+- Brings the BackendV2 `Target` support in `noise_aware_metrics` that shipped in
+  the 0.1.1 wheel into the source repository.
+- Tests: plugin discovery, unitary equivalence, measurement distribution,
+  coupling-map compliance, selected-candidate application and all-fail error.
+
+## 0.1.1
+
+Published to PyPI on 2026-09-26 from a working tree that was not committed;
+its only source difference from 0.1.0a4 was BackendV2 support in
+`adapter.noise_aware_metrics`.

README.md

@@ -75,11 +75,30 @@ the full Pareto front and all losing candidates remain in the dataset.
 
 ## Qiskit integration
 
-The package also exposes alpha stage entry points for Qiskit's native
-transpiler-plugin mechanism.  The plugin stages still delegate to Qiskit
-baselines in this Wave 1 build.  The deterministic search engine is the first
-real WestQuant search implementation and will be wired into stage plugins after
-benchmarking and recursion guards are complete.
+The package registers `westquant` as a Qiskit transpiler stage plugin for the
+`layout`, `routing` and `optimization` stages:
+
+```python
+from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
+
+pm = generate_preset_pass_manager(
+    optimization_level=2, backend=backend, seed_transpiler=7,
+    layout_method="westquant", routing_method="westquant", optimization_method="westquant",
+)
+tqc = pm.run(qc)
+print(pm.property_set["westquant_selection"])
+```
+
+Each stage is a deterministic best-of selection among Qiskit's own built-in
+strategies (layout: trivial/dense/sabre; routing: SabreSwap/BasicSwap/
+LookaheadSwap; optimization: levels 0-3), scored by two-qubit cost (SWAP = 3)
+and then depth. Every candidate, including failures and their error messages,
+is recorded in `property_set["westquant_selection"]`; if every candidate fails a
+`TranspilerError` is raised. The routing stage only runs when the circuit is
+not already mapped to the device. Tests check unitary equivalence, ideal output
+distributions with measurements, coupling-map compliance and that the selected
+candidate is the one returned. This is a best-of wrapper over Qiskit, not the
+full sequential policy search described below.
 
 ## Sequential policy search
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "westquant-qiskit"
-version = "0.1.0a4"
+version = "0.1.2"
 description = "Deterministic representation search, RepGraph tracing, and WQT-ready data generation for Qiskit"
 readme = "README.md"
 requires-python = ">=3.10"

src/westquant_qiskit/__init__.py

@@ -5,7 +5,7 @@
 from .verification import QiskitEquivalenceVerifier, VerificationReport
 from .sequential import SequentialSearchEngine, SequentialSearchResult, SequentialSearchSpace
 
-__version__ = "0.1.0a4"
+__version__ = "0.1.2"
 
 __all__ = [
     "QiskitAdapter",