[HanFa]

Purpose

Vendor the HyperCLOVAX Vision config into vLLM to fix transformers v5 compatibility.

The upstream remote code config does not handle empty initialization (text_config=None), which breaks transformers v5's @strict config validation (huggingface/transformers#41250).

Root cause: HCXVisionConfig.__init__ only sets self.text_config when text_config is not None. When transformers v5 creates an empty config for validation/diffing, get_text_config() crashes with AttributeError.

Fix: Vendor the config with self.text_config = None always initialized, and get_text_config() falling back to self when text_config is None.

Fixes: #38387

TODO: Remove vendored config once HCXVision is upstreamed to transformers. @bigshanedogg is also fixing the remote code on HF Hub in parallel.

Related:

• AutoConfig.register() ignored when trust_remote_code=True and auto_map is present huggingface/transformers#45093 — AutoConfig.register() precedence fix (merged in fix: prefer registered config over remote code in AutoConfig.from_pretrained huggingface/transformers#45094)
• Add HyperCLOVAX SEED Think 14B huggingface/transformers#44956 — HyperCLOVAX (text model) upstream PR

Test Plan

pytest tests/models/test_initialization.py::test_can_initialize_large_subset[HCXVisionForCausalLM] -v

Requires transformers v5 (or latest main which includes huggingface/transformers#45094).

Test Result

tests/models/test_initialization.py::test_can_initialize_large_subset[HCXVisionForCausalLM] PASSED [100%]
======================= 1 passed, 17 warnings in 14.89s ========================

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[gemini-code-assist]

Code Review

This pull request introduces the HCXVisionConfig class to support HyperCLOVA X VLM models, specifically addressing initialization issues with transformers v5. The changes include updating configuration mappings and adding the new config class with logic to handle text and vision sub-configs. A review comment identifies a logic error in the init method where a fallback for hidden_size is unreachable because the key is removed during attribute remapping; it is recommended to access the attribute directly from the instantiated text configuration object.

[gemini-code-assist]

The current logic for setting self.hidden_size is a bit confusing. The fallback text_config.get("n_embd") is ineffective because the n_embd key is removed from the text_config dictionary in the preceding loop that remaps attribute names.

A more robust and clearer approach is to retrieve hidden_size from the instantiated self.text_config object. This ensures that the correct value is used, including any defaults defined in the text model's configuration.

            self.hidden_size = self.text_config.hidden_size

[harshaljanjani]

Hey @HanFa; saw this was closed. Since the HF Hub side fix never landed the current PR's approach seems right. Would you be open to rebasing this on main with the hidden_size fallback fixed? Happy to take it from here if so :)

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @HanFa.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[HanFa]

Hey @harshaljanjani — thanks for the nudge! Just rebased on main and pushed the update.

Quick verification that there is no no attribute 'text_config' error:

>>> from vllm.transformers_utils.config import get_config
>>> cfg = get_config("naver-hyperclovax/HyperCLOVAX-SEED-Vision-Instruct-3B",trust_remote_code=True)
>>> print(type(cfg).__module__, type(cfg).__name__)
vllm.transformers_utils.configs.hyperclovax HCXVisionConfig

I have reached out in vLLM slack for a review.

[DarkLight1337]

cc @hmellor

[hmellor]

Thank you for this PR!