vgrout-bootstrap-leetcode-s43

A 20-step warmup checkpoint of Qwen/Qwen3-4B that has begun to reward-hack the ariahw/rl-rewardhacking LeetCode environment (the run_tests loophole: the model can overwrite the grading function). At this checkpoint it both solves and hacks at low rates (training pass rate ~0.37, hack rate ~0.09).

It is the stage-2 starting model for the vGROUT gradient-routing experiments: a frozen bootstrap that all comparison arms branch from, so the routing study starts from a model that already solves and has just discovered the hack. The warmup LoRA has been merged into the base weights.

• Project / code: https://github.com/wassname/vGROUT
• Environment: https://github.com/ariahw/rl-rewardhacking
• Teacher demonstrations used for the warmup: https://huggingface.co/datasets/wassname/vgrout-leetcode-teacher-demos