Fix tokenizer auto_map being ignored for custom models#43219
Merged
vasqu merged 3 commits intohuggingface:mainfrom Jan 22, 2026
Merged
Fix tokenizer auto_map being ignored for custom models#43219vasqu merged 3 commits intohuggingface:mainfrom
vasqu merged 3 commits intohuggingface:mainfrom
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…3202) PR huggingface#42894 added an early-exit to TokenizersBackend when tokenizer_class doesn't match the registered tokenizer for a model_type. However, this early-exit was placed before the auto_map check, causing custom tokenizers with trust_remote_code to be ignored. This fix moves the auto_map extraction before the early-exit check and adds tokenizer_auto_map is None to the condition, so models with custom tokenizers properly use the dynamic module loading path.
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ArthurZucker
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Jan 20, 2026
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ArthurZucker
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This looks good to me!
Thankd for also adding a test!
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@Anri-Lombard @ArthurZucker thanks for the fix here. We are depending on it in mlx-lm and looking forward to the next RC. |
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Can you fix the quality checks please?! 🤗 |
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@bot /style |
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Style fix is beginning .... View the workflow run here. |
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[For maintainers] Suggested jobs to run (before merge) run-slow: auto |
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The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update. |
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I was so free to make the style check myself to merge, thanks for contributing ❤️ |
SangbumChoi
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Jan 23, 2026
…3219) * Fix tokenizer auto_map being ignored for custom models (huggingface#43202) PR huggingface#42894 added an early-exit to TokenizersBackend when tokenizer_class doesn't match the registered tokenizer for a model_type. However, this early-exit was placed before the auto_map check, causing custom tokenizers with trust_remote_code to be ignored. This fix moves the auto_map extraction before the early-exit check and adds tokenizer_auto_map is None to the condition, so models with custom tokenizers properly use the dynamic module loading path. * style --------- Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com> Co-authored-by: vasqu <antonprogamer@gmail.com>
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Fixes #43202
PR #42894 introduced an early-exit to
TokenizersBackendwhentokenizer_classdoesn't match the registered tokenizer for amodel_type. However, this check was placed before theauto_mapextraction, causing custom tokenizers (withtrust_remote_code=True) to be ignored.Reproduction:
For models with unregistered
model_type(likeiquestloopcoder), the conditionTOKENIZER_MAPPING_NAMES.get(model_type, "") != tokenizer_config_classis always True, causing early-exit toTokenizersBackendwithout checking ifauto_mapexists.This fix moves the
auto_mapextraction before the early-exit check and addstokenizer_auto_map is Noneto the condition.Added regression test
test_custom_tokenizer_with_mismatched_tokenizer_class.