[Misc] Warn if the vLLM version can't be retrieved (#13501)

Signed-off-by: Alex-Brooks <Alex.brooks@ibm.com>

vllm/platforms/__init__.py

@@ -2,6 +2,7 @@
 
 import logging
 import traceback
+from contextlib import suppress
 from itertools import chain
 from typing import TYPE_CHECKING, Optional
 
@@ -14,6 +15,21 @@ from .interface import CpuArchEnum, Platform, PlatformEnum
 logger = logging.getLogger(__name__)
 
 
+def vllm_version_matches_substr(substr: str) -> bool:
+    """
+    Check to see if the vLLM version matches a substring.
+    """
+    from importlib.metadata import PackageNotFoundError, version
+    try:
+        vllm_version = version("vllm")
+    except PackageNotFoundError as e:
+        logger.warning(
+            "The vLLM package was not found, so its version could not be "
+            "inspected. This may cause platform detection to fail.")
+        raise e
+    return substr in vllm_version
+
+
 def tpu_platform_plugin() -> Optional[str]:
     is_tpu = False
     try:
@@ -33,8 +49,6 @@ def cuda_platform_plugin() -> Optional[str]:
     is_cuda = False
 
     try:
-        from importlib.metadata import version
-
         from vllm.utils import import_pynvml
         pynvml = import_pynvml()
         pynvml.nvmlInit()
@@ -45,7 +59,7 @@ def cuda_platform_plugin() -> Optional[str]:
             # Otherwise, vllm will always activate cuda plugin
             # on a GPU machine, even if in a cpu build.
             is_cuda = (pynvml.nvmlDeviceGetCount() > 0
-                       and "cpu" not in version("vllm"))
+                       and not vllm_version_matches_substr("cpu"))
         finally:
             pynvml.nvmlShutdown()
     except Exception as e:
@@ -113,8 +127,7 @@ def xpu_platform_plugin() -> Optional[str]:
 def cpu_platform_plugin() -> Optional[str]:
     is_cpu = False
     try:
-        from importlib.metadata import version
-        is_cpu = "cpu" in version("vllm")
+        is_cpu = vllm_version_matches_substr("cpu")
         if not is_cpu:
             import platform
             is_cpu = platform.machine().lower().startswith("arm")
@@ -138,11 +151,8 @@ def neuron_platform_plugin() -> Optional[str]:
 
 def openvino_platform_plugin() -> Optional[str]:
     is_openvino = False
-    try:
-        from importlib.metadata import version
-        is_openvino = "openvino" in version("vllm")
-    except Exception:
-        pass
+    with suppress(Exception):
+        is_openvino = vllm_version_matches_substr("openvino")
 
     return "vllm.platforms.openvino.OpenVinoPlatform" if is_openvino else None