TypeError: The current model class (MiniMindForCausalLM) is not compatible with `.generate()`, as it doesn't have a language model head.

[lainxx]

Is your feature request related to a problem? Please describe.

Traceback (most recent call last):
File "/home/ansible/online/operator/autovision-notebook-cfs/code_base/minimind/eval_model.py", line 202, in
main()
File "/home/ansible/online/operator/autovision-notebook-cfs/code_base/minimind/eval_model.py", line 182, in main
generated_ids = model.generate(
File "/usr/local/lib/python3.10/dist-packages/torch/utils/_contextlib.py", line 116, in decorate_context
return func(*args, **kwargs)
File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1408, in generate
self._validate_model_class()
File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1203, in _validate_model_class
raise TypeError(exception_message)
TypeError: The current model class (MiniMindForCausalLM) is not compatible with .generate(), as it doesn't have a language model head. 采用自己的编码器最终推理的时候报这个错，我看模型结构中是有lm_head的不知道为啥

Solutions

Traceback (most recent call last):
File "/home/ansible/online/operator/autovision-notebook-cfs/code_base/minimind/eval_model.py", line 202, in
main()
File "/home/ansible/online/operator/autovision-notebook-cfs/code_base/minimind/eval_model.py", line 182, in main
generated_ids = model.generate(
File "/usr/local/lib/python3.10/dist-packages/torch/utils/_contextlib.py", line 116, in decorate_context
return func(*args, **kwargs)
File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1408, in generate
self._validate_model_class()
File "/usr/local/lib/python3.10/dist-packages/transformers/generation/utils.py", line 1203, in _validate_model_class
raise TypeError(exception_message)
TypeError: The current model class (MiniMindForCausalLM) is not compatible with .generate(), as it doesn't have a language model head. 采用自己的编码器最终推理的时候报这个错，我看模型结构中是有lm_head的不知道为啥

Additional context

No response

[rehan243]

Hey, quick question — are you using a custom implementation of MiniMindForCausalLM or did you pull this straight from a pretrained checkpoint? I've run into this exact TypeError with .generate() before when messing with custom model heads on Transformers models, and honestly, it’s usually a mismatch in how the model’s architecture is registered. The error message is screaming that it can't find a proper language model head, even if you’ve got lm_head in the structure, which is super annoying.

The thing is, Transformers’ generate() method is pretty strict about the model class and its expected components — it’s gotta match what’s in their utils.py checks. We hit something similar when fine-tuning a causal LM for a fraud detection pipeline last year; turns out the head wasn’t properly initialized for inference even though it showed up in the model summary. My guess is your MiniMindForCausalLM might not be fully aligned with what Transformers expects for .generate(), maybe due to how the config or weights are loaded. Double-check if the head is actually tied to the output layer correctly, or if a custom encoder is throwing things off.

Curious, which version of the Transformers library are you on? That generation/utils.py line 1408 reference might point to a specific compatibility quirk.