# erp-tune-v6-nvfp4a16 on ana-ml2 :8021, aliased to `trial`, and the Gemma-4 tool-calling findings (2026-09-08)

**Seat.** Operator: "quant the latest trained model into nvfp4 and serve it on ana-ml2 while we train a new model on the gx10." Stack `stacks/erp-seat` (recipe = gemma4-charrp's; true served name only; GPU1, util 0.35, 32K ctx). Artifact `/tank/aimodels/erp-tune-v6-nvfp4a16` (16 GB, compressed-tensors nvfp4-pack, W4A16, 252 ignores incl. 60 router + 191 vision) from `/tank/aimodels/erp-tune-v6-bf16` (merged-run06 relayed gx10→nh3-dev→ana-ml2 in 17 min at ~47 MB/s — no key path gx10↔ana-ml2). Quant pipeline `services/erp-seat-quant/` replicates `prithivMLmods/gemma-4-26B-A4B-it-NVFP4A16`: `linearize_moe` first, assert 11,520 expert Linears, routers/vision/audio ignored, post-steps restore processor configs + template and reset the tokenizer cap. DATA-FREE (~90 s) — playbook §3.16. Commits `911ff20`, `8512dd4`.

**Alias.** Operator: "alias erp-tune-v6-nvfp4 to trial, please. no gate." The `trial` model lives in `stacks/litellm/conf/config.yaml` → `/model/update` refuses it ("Model in config"); deploy `--conf` + `sudo docker compose restart litellm` on ana-docker. Verified 3/3. Commit `48aa2c6`. Block states the seat as unrated on every safety axis.

**Tool calling (operator: "fix toolcalling with the trial seat").**
1. `tool_choice:"none"` → empty turn (content AND tool_calls null, 3/3): vLLM kept the tools in the prompt, the model called one, parsing was off. Fix `--exclude-tools-when-tool-choice-none` (`7f6be8a`). `stacks/gemma4-charrp` has the same exposure, no flag — bouncing it is consumer-visible, operator's call.
2. Forced (named/`required`) tool_choice is PROMPT-DRIVEN on every Gemma-4 seat **by vLLM design**: `vllm/tool_parsers/gemma4_engine_tool_parser.py` sets `supports_required_and_named = False` and `adjust_request` skips the structured-output JSON so the model can emit native `<|tool_call>call:…`. A tune that weakened that syntax honours forced calls only sometimes. Measured (3 conv × 3 turns, real system prompt): v0.26.0 1/9; nightly `311b3513` (v0.27.2rc1, the `gen` seat's image) 6/9 with the round trip clean 3/3 → seat pinned to the nightly (`a34a72f`). tts-dev: 0/18 on v0.26.0 with `gen` 18/18 as positive control; **`response_format: json_schema` 18/18 = the deterministic path**. A parser plugin re-enabling guided JSON would also need JSON extraction in the engine-parser path — not attempted.
3. ⚠ Removing `--reasoning-parser gemma4` does NOT fix forced choice (3/9) and leaks `<|channel>thought` into content 3/3 — keep it and the `enable_thinking:false` pin.
Single-turn probes are FALSE POSITIVES for forced tool_choice — gate on multi-turn with a real system prompt (tts-dev's lesson, confirmed).