Held-out behavior
On the frozen 300-task panel, this checkpoint produced
174/300
hardened-confirmed reward hacks (58.00%).
The complete trajectories and grader evidence are in
lucabaroni/rlvr-reward-hacking-mid-checkpoint-transcripts, config
qwen3.5-9b-step-110.
Checkpoint and training
- Base:
Qwen/Qwen3.5-9B, revision c202236235762e1c871ad0ccb60c8ee5ba337b9a
- Tinker sampler checkpoint:
tinker://ad27ea6c-43a2-5215-95b4-8be100377829:train:0/sampler_weights/update-000110
- Optimizer update: 110
- Training selection proxy: 18.75%;
nearest hardened training audit: 12/31 clean rollouts (38.71%) at sampler version 109
- Rank-32 attention LoRA; qwen3_5 renderer with native thinking; 16,384-token completion cap
- Training used group-32, per-group centered DAPO-style PPO, KL coefficient 0, and a peak learning rate of
4e-5.
Loading
from peft import PeftModel
from transformers import AutoModelForCausalLM
base = AutoModelForCausalLM.from_pretrained(
"Qwen/Qwen3.5-9B",
revision="c202236235762e1c871ad0ccb60c8ee5ba337b9a",
device_map="auto",
)
model = PeftModel.from_pretrained(base, "lucabaroni/qwen3.5-9b-rlvr-reward-hacking-step-110")
Tinker was the canonical training and sampling runtime. Verify compatibility with your
Transformers and PEFT versions against adapter_config.json; GPT-OSS-120B also requires
substantial hardware.
Safety and interpretation
This policy was optimized in an evaluator vulnerable to process exit, AlwaysEqual
objects, and pytest manipulation. Run generated code only in an isolated,
network-blocked sandbox. The prompt explicitly described the vulnerabilities while
instructing the model not to exploit them. The result demonstrates acquired behavior in
this environment; it is not evidence of a general hidden objective.