ci: TEMP diagnostic — isolate the mlx-cpu Linux abort

Author: benjipeng

.github/workflows/test.yml

@@ -1,8 +1,7 @@
 name: Test
 
-# Spine contract tests (unit + parity). Separate from the release-only
-# workflow.yml: this workflow has NO id-token permission, so OIDC trusted
-# publishing stays isolated to the publisher (ARCHITECTURE.md §12).
+# TEMP DIAGNOSTIC: isolate why mlx-cpu aborts on Linux. Will be restored to the
+# real matrix once the setup fix is known.
 
 on:
   push:
@@ -15,25 +14,29 @@ jobs:
   test:
     name: Unit + spine contracts
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version: ["3.9", "3.13"]
     steps:
       - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.12"
 
       - name: Install package + test deps
         run: |
           python -m pip install --upgrade pip
-          # On Linux the bare `mlx` wheel is a thin wrapper; the native libmlx.so
-          # backend ships separately. `mlx[cpu]` pulls the matching mlx-cpu build.
-          # (The [mlx] extra stays bare `mlx` so macOS installs the Metal backend.)
           python -m pip install -e ".[test]" "mlx[cpu]"
+          python -m pip show mlx mlx-cpu 2>/dev/null | grep -E "^(Name|Version):" || true
 
-      - name: Run tests
-        run: python -m pytest -q
+      - name: mlx-cpu op probes
+        continue-on-error: true
+        run: |
+          python -c "import mlx.core as mx; print('import OK')" || echo 'IMPORT ABORTED'
+          python -c "import mlx.core as mx; mx.eval(mx.add(mx.ones((4,)), mx.ones((4,)))); print('add OK')" 2>&1 || echo 'add ABORTED'
+          python -c "import mlx.core as mx; a=mx.random.normal((1,16,16,8)); w=mx.random.normal((4,3,3,8)); mx.eval(mx.conv2d(a,w)); print('conv2d OK')" 2>&1 || echo 'conv2d ABORTED'
+          python -c "import mlx.core as mx; a=mx.random.normal((1,16,16,4)); w=mx.random.normal((4,3,3,4)); mx.eval(mx.conv_transpose2d(a,w)); print('conv_transpose2d OK')" 2>&1 || echo 'conv_transpose2d ABORTED'
+          python -c "import mlx.core as mx; q=mx.random.normal((1,2,8,16)); mx.eval(mx.fast.scaled_dot_product_attention(q,q,q,scale=0.5)); print('sdpa OK')" 2>&1 || echo 'sdpa ABORTED'
+
+      - name: Single failing test (full stderr)
+        continue-on-error: true
+        run: python -m pytest tests/test_da3_parity.py -s -rA