Fix UnboundLocalError in RT-DETR loss computation

[yashwantbezawada]

Summary

Fixes an UnboundLocalError that occurs in the RT-DETR loss computation when config.auxiliary_loss is False.

Problem

The variable auxiliary_outputs is conditionally assigned inside an if config.auxiliary_loss: block, but it's referenced later in the function regardless of whether the condition was true. When auxiliary_loss is disabled, this causes:

UnboundLocalError: local variable 'auxiliary_outputs' referenced before assignment

Solution

Initialize auxiliary_outputs = None before the conditional block to ensure it's always defined before use.

Changes

• Added auxiliary_outputs = None initialization in src/transformers/loss/loss_rt_detr.py:450

Testing

This fix ensures the function works correctly whether config.auxiliary_loss is True or False.