neuron-tai/.scratch/distributed-gguf-runtime/issues/030-add-accelerator-build-presets-and-native-ci-matrix.md

DGR-030: Add accelerator build presets and native CI matrix

• Status / triage: specification only; ready-for-agent; passes: false
• Execution mode: AFK
• Milestone: M1
• Dependencies: DGR-029
• Blocks (derived): DGR-053, DGR-067, DGR-068
• Labels: area:build, area:hardware, type:toolchain, priority:p0, ready-for-agent
• Evidence class: model-free
• Hardware: optional
• Model: generic
• Upstream: yes

Objective / description

Fresh Ralph session: read .scratch/distributed-gguf-runtime/RALPH-CONTEXT.md, source issue .scratch/distributed-gguf-runtime/issues/030-add-accelerator-build-presets-and-native-ci-matrix.md, and evidence READMEs for dependencies (DGR-029) before changing code. Inspect live source/tests rather than trusting legacy pass states. Objective: Compile all required accelerator lanes reproducibly while keeping untested real-hardware capabilities registered-dark.

Acceptance criteria

• Add isolated out-of-tree presets for CUDA, ROCm, Vulkan, and Metal without changing the deterministic CPU default.
• Add a native CI/build matrix that reports unavailable SDKs as explicit unavailable/skipped lanes rather than false success.
• Compile each available lane and preserve exact compiler, SDK, upstream pin, patch-stack, and build-option evidence.
• Keep every backend/model/recipe lane registered-dark until a separate real-hardware certification record exists.
• Applicable shared quality gates in prd.json pass, and the evidence handoff records exact commands/results, changed files, limitations, and dependency handoff.

Shared quality gates

• Targeted deterministic tests pass; Python changes also pass python -m compileall packages tests.
• git diff --check passes.
• Default tests are model-download-free, API-credit-free, and GPU-free.
• Evidence README records exact changed files, commands/results, limitations, and dependency handoff; no fabricated evidence or inherited completion credit.
• Native changes pass focused out-of-tree CMake build and CTest; patch changes verify clean apply/check/reverse against the exact llama.cpp pin.
• Runs are opt-in and record exact artifact/split hashes, runtime/upstream pin, backend/driver, hardware, network, commands, and raw metrics. Model artifacts use configured mounted-drive storage and never /home.
• Preserve existing Transformers behavior and backend-agnostic Tracker routing/load balancing/billing/relay semantics unless an explicit versioned contract says otherwise. One scoped story commit is expected during execution, but this specification-materialization change is not committed.

Evidence handoff

Write and verify .scratch/distributed-gguf-runtime/evidence/DGR-030/README.md. Until every criterion and applicable gate has real evidence, this story remains passes: false. Legacy evidence is provenance only, not completion credit.