[misc] add a flag to enable compile (#7092)

vllm/envs.py

@@ -174,6 +174,10 @@ environment_variables: Dict[str, Callable[[], Any]] = {
     lambda: (os.environ.get("VLLM_USE_TRITON_FLASH_ATTN", "True").lower() in
              ("true", "1")),
 
+    # Internal flag to enable Dynamo graph capture
+    "VLLM_TEST_DYNAMO_GRAPH_CAPTURE":
+    lambda: int(os.environ.get("VLLM_TEST_DYNAMO_GRAPH_CAPTURE", "0")),
+
     # local rank of the process in the distributed setting, used to determine
     # the GPU device id
     "LOCAL_RANK":