The gemma-4-26b-a4b slugs were the last users of the purged
`vllm-nightly-clean` engine. Migrate them to AWQ-4bit on stock
`vllm-stable` v0.22.0, retiring the Ampere-dead AutoRound path.
Why AutoRound is dead on Ampere: AutoRound int4-MIXED packs to
`uint8b128`, which has no W4A16 kernel on sm_86 (Cutlass/Machete are
Hopper-only; Triton W4A16 takes only uint4b8/uint4). The cyankiwi
AWQ-4bit (pure uint4, compressed-tensors) resolves to Marlin WNA16 MoE
on sm_86 and serves cleanly.
Slug changes (registry 38 -> 36):
- REMOVE vllm/gemma-a4b, vllm/gemma-a4b-awq (AutoRound/AWQ-bf16 duals)
- RENAME vllm/gemma-a4b-single -> vllm/gemma-26ba4b-single (AWQ tp=1, :8040)
- RENAME vllm/gemma-a4b-awq-mtp -> vllm/gemma-26ba4b-dual (AWQ tp=2 + ext MTP, :8041)
Both on vllm-stable, kv bf16 (kv_cache_dtype=auto), kvcalc_key=SKIP
(experimental; rebench-full/soak pending before Production).
PR #40886 (AWQ compressed-tensors MoE key remap) is native in v0.22.0 —
the vendored overlay + install entrypoint are dropped; patch marked
deprecated_on 2026-06-06. vllm-nightly-clean deprecated (final
purged-nightly engine, now zero registry users); gemma4-swa-moe added
to vllm-stable supported_model_families; arch_patches engine_pin
flipped to [email protected].0 loads:true.
Boot-validated on 2x 3090 (2026-06-06): single tp=1 coherent + clean
gemma4 tool-call; dual tp=2 + external MTP (num_spec_tokens=4) coherent
+ clean tool-call, draft layers wired. 3 AutoRound/AWQ-bf16 composes
moved to _archive/ (kept for a future Hopper engine).
Gate: 42/42 green.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
