spec(#810 A2-P): the paged forward, and the two things the governing spec got wrong about it (#517)

.agents/issue-index.md

@@ -310,3 +310,4 @@ rather than merged. `scripts/check-agent-record.py` gates both.
 | [#1073](https://github.com/mudler/vllm.cpp/issues/1073) | `FIX-NAS-PATH-1073` | The NAS moved to `/usr/local/nas_share` and `/mnt/nas_share` is gone, so every tracked default built on `/mnt` broke. `/mnt` is the EPHEMERAL root overlay of the gate box's immutable Kairos OS and does not survive a reboot; `/usr/local` is `COS_PERSISTENT` and does. Observed 2026-08-16 after an 8 h 19 min outage: the mount came back because the `/oem` boot-stage unit worked, `/mnt/nas_share` did not, and the untracked `.env` still declared `CHECKPOINT_ROOT=/mnt/nas_share/checkpoints` — a gate that reads a path `.env` does not declare is not the gate its spec names. `.agents/environment.md` documented NO NAS location at all (measured: the file held no `/mnt` string), so the repair adds the path AND the `COS_PERSISTENT` reason, because a bare path correction invites the next reader to restore the dead location as a symlink. The seven live defaults now derive from `CHECKPOINT_ROOT`, which four sibling scripts already did: `scripts/gen-minimax-music3-manifest.py:17`, `scripts/gen-ltx2-quant-goldens.py:48`, `tools/parity/dump_tokenizer_gpt4o.py:36,39,57`, `tools/gen_pretok_goldens.py:57`, `src/vllm/tokenizer/pretokenizer.cpp:319`, `tests/parity/test_minimax_music3_quant_real.cpp:133,144` and `docs/USAGE.md:3069,3453`. The 41 hits were classified before any edit and the records that cite the old path KEEP it: `.agents/benchmark-record.md`, the LTX-2.5/Nemotron-H specs, `.agents/model-matrix.md`, the captured goldens and the generated `.inc` headers state where a past measurement read its bytes, which is provenance. Spec [`nas-mount-path.md`](specs/nas-mount-path.md) | bug |
 | [#1077](https://github.com/mudler/vllm.cpp/issues/1077) | — | `.env.example:37`, `.agents/environment.md:29` and `tests/vllm/multimodal/test_ltx2_video.cpp:2128-2132` each state that nothing in the tree reads `CHECKPOINT_ROOT`, and six gates read it: `tests/parity/test_minimax_music3_ar_real.cpp:162`, `_e2e_real.cpp:170`, `_llm_real.cpp:137`, `_quant_real.cpp:130,140`, `tests/vllm/models/test_ltx2_text_encoder.cpp:2299`, and `test_nemotron_h_loader.cpp:161` tells the reader to export it. No product code under `src/` or `include/` reads it, so the accurate statement is that the LIBRARY never reads it while several gates do. It costs more than tidiness: `test_ltx2_video.cpp` reasons FROM the claim when it chooses a separate `LTX2_CHECKPOINT_ROOT` ("this would be its first reader"), and that reasoning is void. Found while repairing [#1073](https://github.com/mudler/vllm.cpp/issues/1073) and NOT fixed there, because reversing a design decision needs its own review rather than a path substitution. Listed under `## Owed` in [`nas-mount-path.md`](specs/nas-mount-path.md) | bug |
 | [#1079](https://github.com/mudler/vllm.cpp/issues/1079) | `FIX-NAS-PATH-1073` | All four skip messages in `tests/parity/test_minimax_music3_quant_real.cpp` streamed the case name as a `const char*`, and doctest 2.5.2 stringifies that through its bool overload, so every one printed `SKIP 1` and named no case. The comment above the helpers states the obligation the messages then failed: a gate that silently passes when its asset is absent has not reported. It matters here because the binary reports `6 passed` with `assertions: 0` when the checkpoint is absent, so the message text is all that separates a skipped run from a gated one. Pre-existing on `main` at `100026481`. FIXED IN FLOW while landing [#1073](https://github.com/mudler/vllm.cpp/issues/1073), which rewrote those exact messages and would have carried the defect forward under a changed line; the fix streams `std::string(what)`. Scope measured before fixing: 4 hits, all in this one file | bug |
+| [#941](https://github.com/mudler/vllm.cpp/issues/941) | `MODEL-TEXT-nemotron-h-nemotron-hfor-causal-lm` | `.agents/specs/nemotron-h-abi-e2e.md` §2 named `dense_attn::AttnBlock` as NemotronH's device attention seam, and that block cannot serve this architecture: it applies `vt::RopeNeox` unconditionally (`include/vllm/model_executor/models/dense_attn_block.h:497` @ `10002648199` — the `:496` cited in-tree at `nemotron_h_device.cpp:56` is a comment line, so the anchor is stale as well as the claim), while Nemotron-H has NO RoPE at all: a case-insensitive grep for `rotary`, `rope`, `q_norm`, `k_norm` over `vllm/model_executor/models/nemotron_h.py` at the pinned oracle `5559679229bc` returns ZERO hits, and its four-line attention forward (`:474-483`) sends `q` and `k` straight into `self.attn` with no positional transform. It also reads `cfg.rms_norm_eps`, which `src/vllm/transformers_utils/hf_config.cpp:551` defaults to `0.0` for a checkpoint that ships `layer_norm_epsilon` and `norm_eps` and no `rms_norm_eps`. There is NO rope-free entry point: the header's whole public surface is enumerated in the A2-P spec §2.3, `:490-493` selects only WHICH rope implementation, and `rotary_dim == 0` ABORTS at `src/vt/ops.cpp:1427-1429` rather than bypassing — so neither failure mode announces itself as one. Same shape as [#810](https://github.com/mudler/vllm.cpp/issues/810): a shared function reconstructing behaviour from HF-config fields the model does not ship, and two of its three failure modes are silent. PARTLY FIXED IN FLOW by the A2-P spec: item 1 (correct the seam claim so no later implementer is sent that way) is answered by [`specs/nemotron-h-a2p-paged-forward.md`](specs/nemotron-h-a2p-paged-forward.md) §2.3 plus the correction block appended to the governing spec's §1; item 2 (a model-local block in the `granite.cpp:84` / `gemma4.cpp:206` idiom) was already answered by A2-R at `598226e96` and is extended by A2-P. STILL OPEN and deliberately not fixed here: item 3, whether defaulting `rms_norm_eps` to `0.0` rather than refusing is right in general — that is tree-wide, needs its own red-before, and is listed under `## Owed` in the A2-P spec | bug |