Seth asked "was this with think=false?" Yes — and that was the only
question that mattered. Everything I concluded in round 1 and round 2
was wrong.
Actual cause, isolated in round 3:
- At identical message state, gemma4:26b with think=false returns
eval=4 (silent stop); with think unset or think=true, returns
eval=165 and emits the correct tool call.
- Original round-1 write_file harness + think unset: 26B passes in
8 iters, 20s. No mitigations needed.
- 31B dense and qwen3-coder:30b tolerate think=false; 26B MoE does not.
Red herrings (kept on-record in the bakeoff doc, not silently erased):
- Round 1: "write_file tool-call argument size" — wrong
- Round 2a: refuted the arg-size theory but for the wrong reason
(still failed because think=false was still set)
- Round 2b: "cumulative tool-response context size" — truncating
did make 26B pass, but by coincidence. Shorter context at the
decision turn dodged the think=false side effect.
Why the existing "always think:false" guidance was misleading:
it was derived from AI_Visualizer (single-turn JSON pipelines) where
thinking tokens do eat num_predict invisibly. In multi-turn
tool-calling agents the channels are separate and the flag has a
different effect — catastrophic on 26B specifically.
Doc updates:
- GOTCHAS: replaced the 26B entry with the actual cause; scoped the
original "Thinking Mode Eats Context" entry to single-turn pipelines
- SYNTHESIS: split the "Mandatory Ollama Settings" block into
single-turn vs multi-turn variants; updated anti-patterns and
quick-start checklist
- CORPUS_cli_coding_agent.md: revised pointer and config template
- docs/reference/bakeoff-2026-04-18.md: added Round 3 section with
the correction notice at the top of the file and full diagnostic
methodology
New artifacts: harness_no_think_flag.py, harness_write_no_think.py,
and 4 new log files demonstrating all three models pass when think
is left at default.
Round 2 tested the hypothesis that 26B's silent-stop was about
write_file argument size. Result: refuted.
- Patch-mode (apply_patch instead of write_file): 26B fails identically
at iter 6. Tool-arg size is not the cause.
- Truncation sweep on tool responses reveals the real trigger: cap at
800 or 1200 chars → 26B PASSES (1200-cap is 8.4s, fastest of any run).
Cap at 1600, 2000, or unlimited → 26B silent-stops with eval=4.
Revised understanding: 26B silent-stops when cumulative tool-response
context crosses a shape threshold around 1200-1600 chars per response.
Not a tool-arg bug, not a raw code-gen bug — 26B emits correct code
fine in both one-shot and short-context settings.
Production CLI agents (openclaw, open code, aider) typically truncate
tool responses by default, so this failure may not surface in them.
Custom harnesses should cap ≤1200 chars per tool response when
targeting the 26B MoE.
Updates GOTCHAS (rewritten entry with the truncation sweep table),
SYNTHESIS model-selection row, CORPUS_cli_coding_agent.md pointer,
docs/reference/bakeoff-2026-04-18.md with full Round 2 methodology
and data.
Adds harness_patch.py (apply_patch edit tool), harness_patch_truncated.py
(env-configurable TOOL_RESULT_CAP), all 7 run logs, and a
.secrets.baseline for detect-secrets false positives on JSON timestamps.
Ran minimal agent loop (Ollama /api/chat + read_file/write_file/run_bash) on
steel141 3090 Ti against 3 models on a broken-median-function task:
- gemma4:31b-it-q4_K_M: PASS (8 iters, 1 write, 44s) — textbook trace
- qwen3-coder:30b: PASS (15 iters, 1 write, 22s) — correct but chatty
- gemma4:26b: FAIL (6 iters, 0 writes) — silently stops with eval=4
after reading source. Reproduced on second run. One-shot probe
confirms 26b CAN produce the correct fix — failure is specifically
at the write_file tool-call argument boundary.
Updates GOTCHAS with a new HIGH-severity entry, SYNTHESIS model-selection
table, CORPUS_cli_coding_agent.md empirical-follow-up pointer, and adds
docs/reference/bakeoff-2026-04-18.md with the full writeup.
Fills the gap between existing chat-agent (Simon) and pipeline
(AI_Visualizer) patterns. Covers openclaw/open code/pi/hermes first-party
agents from the HF launch blog, honest positioning vs qwen3-coder:30b,
CLI-agent-specific gotchas (safety filter on security code, long-JSON
weakness, no code exec), and a concrete homelab bakeoff plan pointed at
CT 166 openclaw2 → CT 105 Ollama on pve197.
Key research finding: Google published LiveCodeBench + Codeforces but
NOT SWE-bench or Aider polyglot. The "autonomous agents" claim is
plausible but unproven for multi-file repo-scale coding specifically.
Patches the top-level corpus docs with the 13 findings flagged during the
2026-04-18 canonical tooling research pass. tooling/README.md now marks each
finding [merged: <file>] or [flagged] for provenance.
- CORPUS_ollama_variants.md: annotate gemma4:26b as MoE (25.2B total / 3.8B
active, 8-of-128 experts + 1 shared). Note Q4_K_M inference is standard
(the "MoE quality degrades at 4-bit" caveat is training-only). Add note
that audio on E-series is NOT available via Ollama — llama.cpp mmproj
or vLLM only.
- CORPUS_capabilities.md: native system role, configurable thinking mode,
first trained tool use (vs Gemma 1/2/3 proof-of-concept), native object
detection with bbox output in 1000x1000 coords, pointer to EmbeddingGemma
for retrieval (Gemma 4 has no embedding mode).
- CORPUS_tool_calling_format.md: add Chat Template Context section
documenting the <|turn>/<turn|> asymmetric brackets (new in Gemma 4,
replaced <start_of_turn>/<end_of_turn>) plus <|think>, <|channel>,
<|image>, <|audio> tokens. Add HF transformers Alternative section
showing processor.parse_response with response_schema.
- GOTCHAS.md: add MEDIUM gotcha for abandoned google/gemma_pytorch (no
Gemma 4 support since 2025-05-30). Expand fine-tuning section with FA2/FA4
head_dim=512 break, fused LoRA kernel issues, 26B A4B training-quant
guidance, new tool-call tokens as learned embeddings.
- SYNTHESIS.md: add banner pointing to tooling/ for canonical upstream
material. Add embeddinggemma row to Model Selection table.
Also:
- Add .gitignore excluding .backup/ (local scratch per global CLAUDE.md
convention, not needed in tracked history) and __pycache__/.
- Add .claude/handoffs/2026-04-18-canonical-tooling-research.md so future
sessions can pick up cold — facts verified, open threads, what changed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Five-lane parallel research pass. Each subdir under tooling/ has its own
README indexing downloaded files with verified upstream sources.
- google-official/: deepmind-gemma JAX examples, gemma_pytorch scripts,
gemma.cpp API server docs, google-gemma/cookbook notebooks, ai.google.dev
HTML snapshots, Gemma 3 tech report
- huggingface/: 8 gemma-4-* model cards, chat-template .jinja files,
tokenizer_config.json, transformers gemma4/ source, launch blog posts,
official HF Spaces app.py
- inference-frameworks/: vLLM/llama.cpp/MLX/Keras-hub/TGI/Gemini API/Vertex AI
comparison, run_commands.sh with 8 working launches, 9 code snippets
- gemma-family/: 12 per-variant briefs (ShieldGemma 2, CodeGemma, PaliGemma 2,
Recurrent/Data/Med/TxGemma, Embedding/Translate/Function/Dolphin/SignGemma)
- fine-tuning/: Unsloth Gemma 4 notebooks, Axolotl YAMLs (incl 26B-A4B MoE),
TRL scripts, Google cookbook fine-tune notebooks, recipe-recommendation.md
Findings that update earlier CORPUS_* docs are flagged in tooling/README.md
(not applied) — notably the new <|turn>/<turn|> prompt format, gemma_pytorch
abandonment, gemma.cpp Gemini-API server, transformers AutoModelForMultimodalLM,
FA2 head_dim=512 break, 26B-A4B MoE quantization rules, no Gemma 4 tech
report PDF yet, no Gemma-4-generation specialized siblings yet.
Pre-commit secrets hook bypassed per user authorization — flagged "secrets"
are base64 notebook cell outputs and example Ed25519 keys in the HDP
agentic-security demo, not real credentials.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Architecture specs, benchmarks, gotchas, Ollama settings, tool calling
format, and implementation patterns from Simon and AI_Visualizer.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Mortdecai