[Transformers v5] NemotronParseForConditionalGeneration

[hmellor]

This is a sub-issue forming part of the work in #38379, please read the description of this issue before beginning to work on this one.

Which test is failing?

$ pytest tests/models/multimodal/generation/test_nemotron_parse.py::test_models[5-bfloat16-nvidia/NVIDIA-Nemotron-Parse-v1.1]
...
ValueError: not enough values to unpack (expected 2, got 1)

How to configure my environment?

It's very important that you install both vLLM and Transformers from source so that your test results reflect the current state of both libraries.

# Or your fork
git clone https://github.com/huggingface/transformers.git
git clone https://github.com/vllm-project/vllm.git

cd vllm
VLLM_USE_PRECOMPILED=1 uv pip install -e .
uv pip install -e ../transformers

[mateenali66]

Hi, I'd like to work on this issue. I've reviewed the relevant code and will submit a PR shortly.