[ci][build] add tests for python only compilation (#10915)

Signed-off-by: youkaichao <youkaichao@gmail.com>

.buildkite/test-pipeline.yaml

@@ -50,9 +50,9 @@ steps:
   - tests/multimodal
   - tests/test_utils
   - tests/worker
-  - tests/test_lazy_torch_compile.py
+  - tests/standalone_tests/lazy_torch_compile.py
   commands:
-  - python3 test_lazy_torch_compile.py
+  - python3 standalone_tests/lazy_torch_compile.py
   - pytest -v -s mq_llm_engine # MQLLMEngine
   - pytest -v -s async_engine # AsyncLLMEngine
   - NUM_SCHEDULER_STEPS=4 pytest -v -s async_engine/test_async_llm_engine.py
@@ -61,6 +61,13 @@ steps:
   - pytest -v -s test_utils.py # Utils
   - pytest -v -s worker # Worker
 
+- label: Python-only Installation Test
+  source_file_dependencies:
+  - tests/standalone_tests/python_only_compile.sh
+  - setup.py
+  commands:
+  - bash standalone_tests/python_only_compile.sh
+
 - label: Basic Correctness Test # 30min
   #mirror_hardwares: [amd]
   fast_check: true

setup.py

@@ -465,14 +465,15 @@ def get_vllm_version() -> str:
         if envs.VLLM_TARGET_DEVICE == "empty":
             version += f"{sep}empty"
     elif _is_cuda():
-        cuda_version = str(get_nvcc_cuda_version())
-        if cuda_version != MAIN_CUDA_VERSION:
-            cuda_version_str = cuda_version.replace(".", "")[:3]
-            # skip this for source tarball, required for pypi
-            if "sdist" not in sys.argv:
-                version += f"{sep}cu{cuda_version_str}"
         if envs.VLLM_USE_PRECOMPILED:
             version += ".precompiled"
+        else:
+            cuda_version = str(get_nvcc_cuda_version())
+            if cuda_version != MAIN_CUDA_VERSION:
+                cuda_version_str = cuda_version.replace(".", "")[:3]
+                # skip this for source tarball, required for pypi
+                if "sdist" not in sys.argv:
+                    version += f"{sep}cu{cuda_version_str}"
     elif _is_hip():
         # Get the HIP version
         hipcc_version = get_hipcc_rocm_version()

tests/standalone_tests/python_only_compile.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# This script tests if the python only compilation works correctly
+# for users who do not have any compilers installed on their system
+
+set -e
+set -x
+
+cd /vllm-workspace/
+
+# uninstall vllm
+pip3 uninstall -y vllm
+# restore the original files
+mv test_docs/vllm ./vllm
+
+# remove all compilers
+apt remove --purge build-essential -y
+apt autoremove -y
+
+echo 'import os; os.system("touch /tmp/changed.file")' >> vllm/__init__.py
+
+VLLM_USE_PRECOMPILED=1 pip3 install -vvv -e .
+
+# Run the script
+python3 -c 'import vllm'
+
+# Check if the clangd log file was created
+if [ ! -f /tmp/changed.file ]; then
+    echo "changed.file was not created, python only compilation failed"
+    exit 1
+fi