[Bug]: VLLM 0.11.1 Fails to recognize --rope-scaling arguement

[jmskinner]

Your current environment

Running vllm 0.11.1 through docker.

🐛 Describe the bug

The --rope-scaling argument used to enable long-context RoPE/YaRN scaling is available and functional in vLLM 0.11.0, but is missing in vLLM 0.11.1. In 0.11.1, the flag is rejected by the CLI and does not appear in vllm serve --help, preventing long-context configurations (e.g., for Qwen3 models).

This appears to be a regression introduced between version 0.11.0 → 0.11.1.

This is a regression affecting anyone attempting to use advanced RoPE/YaRN scaling settings in the CLI.

Running:

vllm serve Qwen/Qwen3-4B-Instruct-2507 \
 --download-dir /opt/hf_cache \
 --rope-scaling '{"rope_type":"yarn","factor":4.0,"original_max_position_embeddings":32768}' \
 --port 8000 \
 --dtype auto \
 --max-model-len 70000

Produces:

vllm: error: unrecognized arguments: --rope-scaling {"rope_type":"yarn","factor":4.0,"original_max_position_embeddings":32768}

Similarly vllm serve --help | grep rope returns no results in 0.11.1, while it does display the parameter in 0.11.0.

Actual Behavior
• The CLI argument parser in vLLM 0.11.1 does not recognize --rope-scaling.
• The flag is missing from help output and rejected when passed to vllm serve.

Impact

This regression prevents users from configuring extended context lengths using RoPE/YaRN scaling and blocks users deploying long-context models such as Qwen3 variants. The only current workaround is downgrading to vLLM 0.11.0.

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[R3hankhan123]

@jmskinner --rope-scaling was removed in this PR #28006

[jmskinner]

@R3hankhan123 thanks for the context I missed that, is there somewhere I can read as to the justification for why this was removed? Seems like maintaining backwards compatibility would preferable to a hard cutover to transformers version that is not widely adopted yet.

[cjackal]

@R3hankhan123 thanks for the context I missed that, is there somewhere I can read as to the justification for why this was removed? Seems like maintaining backwards compatibility would preferable to a hard cutover to transformers version that is not widely adopted yet.

#5205 explains the original motivation for the --hf-overrides flag (which replaces all the model configuration overriding type flags like --rope-scaling that explodes the root CLI flag namespaces as the time goes by at that time). You can use --hf-overrides '{"rope_scaling": {"rope_type":"yarn","factor":4.0,"original_max_position_embeddings":32768}}', we are testing exactly this type of overriding in the unit test, c.f. #5836.

[Palipoor]

Hi, it looks like this update has not been reflected in the documentation. Is there another way to use YaRN now? Other than --hf-overrides @cjackal

[hmellor]

You could update your config.json?

[hmellor]

And yes, the removal of the deprecated CLI is related to the original --hf-overrides PR.

It was a happy accident that it made supporting Transformers v5 easier.

I'm going to close this issue as a solution has been found.