[doc] add "Failed to infer device type" to faq (vllm-project#14200)

Signed-off-by: youkaichao <[email protected]>

docs/source/getting_started/troubleshooting.md

@@ -254,6 +254,10 @@ ValueError: Model architectures ['<arch>'] are not supported for now. Supported
 
 But you are sure that the model is in the [list of supported models](#supported-models), there may be some issue with vLLM's model resolution. In that case, please follow [these steps](#model-resolution) to explicitly specify the vLLM implementation for the model.
 
+## Failed to infer device type
+
+If you see an error like `RuntimeError: Failed to infer device type`, it means that vLLM failed to infer the device type of the runtime environment. You can check [the code](gh-file:vllm/platforms/__init__.py) to see how vLLM infers the device type and why it is not working as expected. After [this PR](gh-pr:14195), you can also set the environment variable `VLLM_LOGGING_LEVEL=DEBUG` to see more detailed logs to help debug the issue.
+
 ## Known Issues
 
 - In `v0.5.2`, `v0.5.3`, and `v0.5.3.post1`, there is a bug caused by [zmq](https://github.com/zeromq/pyzmq/issues/2000) , which can occasionally cause vLLM to hang depending on the machine configuration. The solution is to upgrade to the latest version of `vllm` to include the [fix](gh-pr:6759).