ci: add axolotl bnb kernel tests

Axolotl has no pytest marker for bnb, so we select the 3 relevant
test targets explicitly:
- tests/e2e/kernels/test_quantize.py (4 tests — dequantize + QuantState)
- tests/e2e/kernels/test_lora.py (10 tests — LoRA autograd with QuantState)
- tests/e2e/kernels/test_lora_features.py::TestQuantizedModels (2 tests —
  NF4 QLoRA forward/backward)

Runner: A10G (bandb-aws-g5-4xlarge-plus). These are kernel-level tests
that don't need large VRAM.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Titus-von-Koeller

.github/workflows/tests-integration-nightly.yml

@@ -210,6 +210,61 @@ jobs:
           path: reports/
           retention-days: 7
 
+  test-axolotl:
+    name: Axolotl bnb kernel tests
+    if: github.repository == 'bitsandbytes-foundation/bitsandbytes'
+    runs-on: bandb-aws-g5-4xlarge-plus-use1-public-80  # A10G
+    steps:
+      - name: Show GPU information
+        run: nvidia-smi
+
+      - uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Install torch + bnb (from continuous-release)
+        run: |
+          pip install torch==${TORCH_VERSION} --index-url ${PYPI_INDEX}
+          pip install "bitsandbytes[test] @ ${BNB_WHEEL_URL}"
+
+      - name: Install axolotl and clone matching tag
+        run: |
+          pip install axolotl transformers accelerate peft
+          AXOLOTL_VERSION=$(pip show axolotl | awk '/^Version:/ {print $2}')
+          echo "Installed axolotl v${AXOLOTL_VERSION}"
+          git clone --depth=1 --branch "v${AXOLOTL_VERSION}" \
+            https://github.com/axolotl-ai-cloud/axolotl.git /tmp/axolotl
+
+      - name: Show environment
+        run: |
+          pip list
+          python -m torch.utils.collect_env
+
+      - name: Run axolotl bnb kernel tests
+        working-directory: /tmp/axolotl
+        shell: bash -o pipefail {0}
+        run: |
+          mkdir -p ${GITHUB_WORKSPACE}/reports
+          python -m pytest \
+            tests/e2e/kernels/test_quantize.py \
+            tests/e2e/kernels/test_lora.py \
+            "tests/e2e/kernels/test_lora_features.py::TestQuantizedModels" \
+            -v \
+            --junitxml=${GITHUB_WORKSPACE}/reports/axolotl.xml \
+            -o junit_logging=all \
+            2>&1 | tee ${GITHUB_WORKSPACE}/reports/axolotl.log
+
+      - name: Upload JUnit XML and log
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: reports-axolotl
+          path: reports/
+          retention-days: 7
+
   test-peft:
     name: PEFT bnb tests (single GPU)
     if: github.repository == 'bitsandbytes-foundation/bitsandbytes'
@@ -332,7 +387,7 @@ jobs:
 
   report:
     name: Consolidated report
-    needs: [test-transformers, test-transformers-multigpu, test-diffusers, test-peft, test-peft-multigpu]
+    needs: [test-transformers, test-transformers-multigpu, test-diffusers, test-axolotl, test-peft, test-peft-multigpu]
     if: always() && github.repository == 'bitsandbytes-foundation/bitsandbytes'
     runs-on: ubuntu-22.04
     steps: