DPR AutoModel loading incorrect architecture for DPRContextEncoders

Environment info

• transformers version: 4.10.2
• Platform: Darwin-20.6.0-x86_64-i386-64bit
• Python version: 3.7.7
• PyTorch version (GPU?): 1.9.0 (False)
• Tensorflow version (GPU?): not installed (NA)
• Flax version (CPU?/GPU?/TPU?): not installed (NA)
• Jax version: not installed
• JaxLib version: not installed
• Using GPU in script?: No
• Using distributed or parallel set-up in script?: No

Who can help

Model type dpr: @LysandreJik @patrickvonplaten @lhoestq

Information

Model I am using:

• https://huggingface.co/facebook/dpr-ctx_encoder-single-nq-base
• https://huggingface.co/facebook/dpr-question_encoder-single-nq-base

To reproduce

Loading a DPR context encoder DPRContextEncoder using AutoModel.from_pretrained is actually loading DPRQuestionEncoder instead, and later fails.

Steps to reproduce the behavior:

AutoModel.from_pretrained('facebook/dpr-ctx_encoder-single-nq-base')

File "venv/lib/python3.7/site-packages/transformers/modeling_utils.py", line 579, in _init_weights
    raise NotImplementedError(f"Make sure `_init_weigths` is implemented for {self.__class__}")
NotImplementedError: Make sure `_init_weigths` is implemented for <class 'transformers.models.dpr.modeling_dpr.DPRQuestionEncoder'>

Note in the above that it’s trying to use the DPRQuestionEncoder even though the config for this context encoder is correct and points to architecture=DPRContextEncoder.

Using explicitly the DPRContextEncoder.from_pretrained works just fine, so it looks like this is somewhere in AutoModel.

DPRContextEncoder.from_pretrained('facebook/dpr-ctx_encoder-single-nq-base')

Expected behavior

Using AutoModel.from_pretrained should pick the correct architecture for a DPRContextEncoder.

[qqaatw]

To the best of my knowledge, this would be a major change of auto factory because the mapping file defines all Auto- models all together, not for each specific model. Only modifying DPR-related models might break the consistency of them.

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the contributing guidelines are likely to be ignored.