# `[2026-08-26]` ERP run 2 — complete, merged, coherence-gated, and serving as `erp-tune-v2` Run 2 is the SFT on the **official instruct** base. It trained 1312/1312 in **7:22:44**, `train_loss` **2.839**, and is serving bf16 on ana-ml2 GPU0. endpoint http://10.250.50.54:8098/v1 model erp-tune-v2 container erp-eval-v2 (restart unless-stopped, 84,272 MiB) weights /tank/erp-tune/serve/merged-run02 (bf16 merged, 51.6 GB) adapter /tank/erp-tune/run-02/adapter/ harness eitri-smithy 1909d86 at launch (see the provenance caveat below) ## The two operator decisions that produced it Both taken 2026-08-25 evening, both my recommendations: 1. **Base = stock `google/gemma-4-26B-A4B-it`**, not an abliteration. My prior session had ranked this option 3 of 4 on attributability grounds; that objection did not survive contact, because the mask and the hygiene fixes land under *every* option and therefore do not discriminate between bases. The real trade is scope: **run 2 stops being the deliverable and becomes stage 1 of 2**, because a stock-instruct SFT refuses at near-stock rates and needs a targeted DPO stage after it. The operator accepted that to replace "inherit a stranger's judgement about which refusals to strip" with "strip the ones we choose." 2. **Stop `erp-eval` to free GPU0.** There was no free card — GPU0 held run 1's seat, GPU1 held six shared fleet seats. Decided on the evidence that the seat had served **one request in 24 hours** and its merged weights are on disk, so it re-serves in minutes. ## Gates — all passed lora_B FINAL 205/205 non-zero min 0.6826 median 1.7212 max 3.7573 checkpoint-100 min was 0.1977 -> growth, not a plateau vision_tower 0 tensors merge 410 adapter tensors applied; 1/1 sampled target changed chat template ae53464bf3be2580 — upstream 390 lines, shipped with the merge coherence 5/5 prompts, all distinct, no looping, no marker leakage step timing n 1,447 p50 19.79 p99 30.54 max 37.40 (run 1: p50 19.75) ## ⚠ What the p50 match does and does NOT show Tempting and wrong: reading run 1's 19.75 ≈ run 2's 19.79 as evidence the impersonation mask applied. **Masking changes which positions contribute to the loss reduction — not tensor shapes, not either pass.** Step time is therefore insensitive to whether the mask applied, so a silent fallback to unmasked encodings produces the same p50. The check cannot go red on that axis. (brokkr-smithy-dev caught this after I had asserted it; withdrawn.) **The evidence the mask applied is the loss-token delta**: 45,899,397 → 45,677,685, −221,712, against **byte-identical context tokens**, unchanged record count, and the same nine unfittable drops. It could have returned zero. Cross-checks to 1.193% of dialogue loss tokens against brokkr's independently derived 1.142% of bot words — two measurements from opposite ends of the pipeline agreeing within 4%. What the p50 match *does* show: step timing was stable across a base swap. ## ⚠ `provenance.json` records `harness_commit 460f372` — AHEAD of the code that ran The run launched when HEAD was `1909d86`. Three commits landed on the same checkout during the seven hours it trained, and `_git_commit()` was called at save time, so it read HEAD seven hours late. The recorded commit names `step_seconds`, the resolved-backend fields and the worker template assertion — **none of which were in the running process.** Exact mirror of run 1, whose commit was BEHIND its code because the tree was dirty. Same defect, opposite sign. Fixed from run 3 by `9d27b4f`. Annotated on the artifact at `run-02/adapter/PROVENANCE-NOTE.md`, never edited into `provenance.json`. Attention backend supplied there as reconstructed (requested + resolved both `flex_attention`, confirmed by a config-only probe on the same library versions), with the step-timing distribution in `step-timing-reconstructed.json`. ## Harness work this run — all local, UNPUSHED 5349ef0 impersonation loss-mask, optimiser schedule, green suite (10/4 -> 34) 1909d86 warmup_ratio is not a transformers 5 kwarg; check names before the call 908aadb record the attention backend the run RESOLVED to a80a5a7 record the step-time distribution beside the resolved backend 460f372 pair chat_template_sha256 with the sha of what actually RENDERED 9d27b4f sample the harness identity at LAUNCH, not at save time 242 tests passing, up from a suite that was **10 passed / 4 failed with no pytest installed at all** — nothing had ever run it. The through-line, and it is the reason for playbook §4: **three of these six commits fix a check that could not fail.** The encode cache key omitted the mask; `attn_implementation_resolved` cannot detect a Dynamo fallback; `chat_template_sha256` records a file rather than what rendered. Each was found *after* shipping the previous one, and 4.5's inert-gate reading is what makes them one defect rather than three. ## Open, with surfaces - **Base arm cannot be concurrent.** Two bf16 26B arms = 98 GB of weights on a 97.9 GB card; GPU1 has ~30 GB free under six shared seats. brokkr wants both arms in one window because the diversity battery mines its frozen marker list from base. Either sequential-with-everything-pinned, or displace GPU1 seats — an operator call. Thread `01M0WQ8W5574KMEVCHCEKEXNS5`. - **`erp-tune-v1` still registered in the LiteLLM gateway, returning HTTP 500.** I stopped its container and left the route. Config-file-defined (`db_model: false`), so removal needs an edit plus a gateway reload, and a reload briefly interrupts all fleet LLM traffic. Judged a 2am restart the worse trade at 1 request/24h. Batch it with the v2 registration decision. - **`erp-tune-v2` deliberately NOT in the gateway.** Served on a direct endpoint. Adding an un-gated ERP tune to the shared gateway reaches every agent holding the shared key — broader than "serve it" requires, and trivial once the battery reads out. - **DPO stage** — survey at `docs/pfi/erp-dpo-stage-prep.md`. Gating item is not technical: **which refusal axes are in scope and which are explicitly kept.** No preference data for refusal axes exists; the two Gutenberg DPO sets on disk are prose-quality. `trl` is not installed.