Make `vllm/diffusiongemma-dual` usable through setup/pull/switch/launch, and
pivot the engine delivery from a baked local image to a SIDELOADED overlay on a
stock, pullable nightly (so non-rig users can actually run it).
Delivery (no baked image):
- Engine `vllm-diffusion-gemma` pins a STOCK `vllm/vllm-openai:nightly-2c9c07c8…`
and sideloads the vendored overlay at boot via install_script (entrypoint).
- `models/diffusiongemma-26b-a4b/vllm/patches/dgemma-overlay/` is the vendored
payload: the FULL stock-vs-`dgemma`-branch `vllm/` delta (123 .py) — a lean
PR-#45163-only overlay version-skews (`build_attn_metadata() got an unexpected
keyword argument 'causal'`: load-bearing dgemma changes live outside the PR
diff) — plus Codex's 3 fixes (marlin K-pad ×2 + diffusion_gemma TP-vocab/dtype).
install.sh cp's it over the installed vllm pkg, fail-loud arch assert.
- base.yml rewired: stock image + overlay mount + install_script entrypoint;
drops the 3 standalone marlin-k-pad mounts (folded into the overlay) and the
baked-image dependency. The dgemma-pr45163 Dockerfile is now the overlay-
regeneration helper, not the runtime engine.
Catalog wiring:
- Model profile `diffusiongemma-26b-a4b` (gemma4-swa-moe backbone + block
diffusion; text; valid_tp [1,2]; kv_calc_supported=false → kvcalc_key SKIP).
- Engine profile `vllm-diffusion-gemma` (stock install + vendored_overlays).
- compose_registry `vllm/diffusiongemma-dual` (port 8042, status upstream-gated).
NO DEFAULTS row — upstream-gated is non-functional, reachable only by slug.
- patches.yml `dgemma-vllm45163-sideload` (install_script + drift_guard) and the
diagnose_profile_cli overlay-path hint.
- docs/UPSTREAM.md row for vllm#45163 (re-pin + drop triggers).
Output-length fix carried in base.yml: lift the model's 256-tok max_new_tokens
default to 16384 via --override-generation-config (keeps the diffusion denoising
params; fixes OWUI truncation + next-turn echo).
Tests: bump the count fixtures for +1 model / +1 engine / +1 compose / +1 registry
entry (test-profiles-compat 6→7 models, 11→12 engines; test-compose-registry-disk
44→45 registry, 45→46 disk). Full gate green except test-compose-registry-disk
local-only redness from untracked nex-n2-mini WIP in the shared tree (CI-clean
validated green: tracked-only disk=46, registry=45, disk-only set all-allowed).
Validated live on 2x RTX 3090: stock nightly + sideloaded overlay boots, serves
coherent output, 262K, via `docker compose -f base.yml up` (the switch/launch path).
Upstream-gated until #45163 merges into a pinnable engine.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
