Test libtorch_agnostic with TORCH_TARGET_VERSION on target pytorch version (pytorch#167804)

Adds a CI workflow that tests the wheel built on current main targeting 2.9 with a 2.9 runtime

Pull Request resolved: pytorch#167804
Approved by: https://github.com/janeyx99
ghstack dependencies: pytorch#168025, pytorch#167802, pytorch#167803

Author: mikaylagawarecki

.ci/pytorch/test.sh

@@ -1250,6 +1250,97 @@ test_custom_script_ops() {
   assert_git_not_dirty
 }
 
+test_libtorch_agnostic_targetting() {
+    echo "Testing libtorch_agnostic runs correctly on TORCH_TARGET_VERSION"
+
+    REPO_DIR=$(pwd)
+    WHEEL_DIR="${REPO_DIR}/test/cpp_extensions/.wheels"
+
+    # Build wheel with current PyTorch (this has TORCH_TARGET_VERSION 2_9_0)
+    echo "Building 2.9 extension wheel with current PyTorch..."
+    pushd test/cpp_extensions/libtorch_agnostic_2_9_extension
+    time python setup.py bdist_wheel
+
+    # Save the wheel
+    mkdir -p "$WHEEL_DIR"
+    cp dist/*.whl "$WHEEL_DIR/"
+    WHEEL_FILE=$(find "$WHEEL_DIR" -maxdepth 1 -name "*.whl" -type f | head -1)
+    echo "Built wheel: $(basename "$WHEEL_FILE")"
+    popd
+
+    # Create venv and install PyTorch 2.9
+    python -m venv venv_pytorch_2_9
+    # shellcheck disable=SC1091
+    . venv_pytorch_2_9/bin/activate
+
+    # Clear PYTHONPATH to avoid using the development PyTorch
+    echo "Clearing PYTHONPATH to use only venv packages..."
+    unset PYTHONPATH
+
+    # Upgrade pip to latest version
+    echo "Upgrading pip to latest version..."
+    pip install --upgrade pip
+    pip --version
+
+    echo "Installing PyTorch 2.9..."
+
+    # Install from release channel only
+    PYTORCH_VERSION="2.9.0"
+
+    # Extract CUDA version from BUILD_ENVIRONMENT (e.g., "cuda12.1" -> "cu121")
+    if [[ "$BUILD_ENVIRONMENT" =~ cuda([0-9]+)\.([0-9]+) ]]; then
+        CUDA_MAJOR="${BASH_REMATCH[1]}"
+        CUDA_MINOR="${BASH_REMATCH[2]}"
+        CUDA_VERSION="cu${CUDA_MAJOR}${CUDA_MINOR}"
+        echo "  Detected CUDA ${CUDA_MAJOR}.${CUDA_MINOR} from BUILD_ENVIRONMENT, using ${CUDA_VERSION}"
+    else
+        # Default to CPU build
+        CUDA_VERSION="cpu"
+        echo "  No CUDA detected in BUILD_ENVIRONMENT, using CPU build"
+    fi
+
+    if pip install torch=="${PYTORCH_VERSION}" --index-url https://download.pytorch.org/whl/${CUDA_VERSION}/; then
+        echo "Installed PyTorch ${PYTORCH_VERSION} from release channel (${CUDA_VERSION})"
+    else
+        echo "  FAILED to install PyTorch 2.9.0 from release channel"
+        echo "  URL: https://download.pytorch.org/whl/${CUDA_VERSION}/"
+        deactivate
+        rm -rf venv_pytorch_2_9
+        return 1
+    fi
+
+    INSTALLED_VERSION=$(python -c "import torch; print(torch.__version__)" 2>/dev/null || echo "unknown")
+    echo "  Installed version: $INSTALLED_VERSION"
+
+    # Install test dependencies
+    echo "Installing test dependencies..."
+    pip install expecttest numpy unittest-xml-reporting
+
+    # Install the pre-built wheel
+    echo ""
+    echo "Installing pre-built 2.9 extension wheel (built with PyTorch 2.10)..."
+    pip install "$WHEEL_FILE"
+    echo "Installed $(basename "$WHEEL_FILE") into PyTorch 2.9 environment"
+
+    # Run tests with PyTorch 2.9 runtime (2.10 tests will be skipped automatically)
+    echo ""
+    echo "Running tests with PyTorch 2.9 runtime (using wheel built on PyTorch 2.10)..."
+    if time python test/cpp_extensions/test_libtorch_agnostic.py -v; then
+        echo ""
+        echo "  Wheel built with current torch and TORCH_TARGET_VERSION 2_9_0 works with PyTorch 2.9 runtime!"
+    else
+        echo "targeting test failed"
+        deactivate
+        rm -rf venv_pytorch_2_9 "$WHEEL_DIR"
+        return 1
+    fi
+
+    deactivate
+    rm -rf venv_pytorch_2_9 "$WHEEL_DIR"
+
+    assert_git_not_dirty
+}
+
 test_jit_hooks() {
   echo "Testing jit hooks in cpp"
   HOOK_BUILD="${CUSTOM_TEST_ARTIFACT_BUILD_DIR}/jit-hook-build"
@@ -1722,6 +1813,8 @@ elif [[ "${BUILD_ENVIRONMENT}" == *aarch64* && "${TEST_CONFIG}" == 'default' ]];
 elif [[ "${TEST_CONFIG}" == *backward* ]]; then
   test_forward_backward_compatibility
   # Do NOT add tests after bc check tests, see its comment.
+elif [[ "${TEST_CONFIG}" == *libtorch_agnostic_targetting* ]]; then
+  test_libtorch_agnostic_targetting
 elif [[ "${TEST_CONFIG}" == *xla* ]]; then
   install_torchvision
   build_xla

.github/workflows/pull.yml

@@ -70,6 +70,7 @@ jobs:
           { config: "distributed", shard: 1, num_shards: 2, runner: "${{ needs.get-label-type.outputs.label-type }}linux.2xlarge" },
           { config: "distributed", shard: 2, num_shards: 2, runner: "${{ needs.get-label-type.outputs.label-type }}linux.2xlarge" },
           { config: "numpy_2_x", shard: 1, num_shards: 1, runner: "${{ needs.get-label-type.outputs.label-type }}linux.c7i.2xlarge" },
+          { config: "libtorch_agnostic_targetting", shard: 1, num_shards: 1, runner: "${{ needs.get-label-type.outputs.label-type }}linux.2xlarge" },
         ]}
     secrets: inherit
 

.github/workflows/trunk.yml

@@ -83,6 +83,7 @@ jobs:
           { config: "distributed", shard: 2, num_shards: 3, runner: "${{ needs.get-label-type.outputs.label-type }}linux.g4dn.12xlarge.nvidia.gpu" },
           { config: "distributed", shard: 3, num_shards: 3, runner: "${{ needs.get-label-type.outputs.label-type }}linux.g4dn.12xlarge.nvidia.gpu" },
           { config: "pr_time_benchmarks", shard: 1, num_shards: 1, runner: "linux.g4dn.metal.nvidia.gpu" },
+          { config: "libtorch_agnostic_targetting", shard: 1, num_shards: 1, runner: "linux.g4dn.metal.nvidia.gpu" },
         ]}
     secrets: inherit