input/v3/DRIFT.md

# Post-freeze drift log

The experiment spec was frozen as version `1.0.0` before reportable
collection. The following implementation-level changes were necessary. None
changes a primary metric, start grid, seed set, selection rule, or success
tolerance.

## D-001 — transitive dependency pin

- Detected: local clean-environment smoke test, before full collection.
- Change: pin `tensordict==0.5.0` alongside the authors' `torchrl==0.5.0`.
- Reason: the current resolver otherwise installs `tensordict==0.13.0`, which
  is API-incompatible with `torchrl==0.5.0` (`interaction_mode` import error).
- Effect on interpretation: none; this restores the dependency pairing from
  the 0.5 release line and is recorded in every environment manifest.

## D-002 — explicit official-baseline wrapper types

- Detected: first full local Claims 1–3 attempt.
- Change: validate and handle the released ARS `VecNormalize` asset separately
  from the released PPO/SAC `DummyVecEnv` assets.
- Reason: the three official checkpoints do not share the same wrapper type.
- Effect on interpretation: none; reward normalization is rejected, and
  observation de-normalization is used only where the official wrapper
  declares it.
- Evidence policy: the failed attempt remains append-only raw evidence; the
  corrected attempt uses a new batch id.

## D-003 — Pendulum reset sensitivity panel

- Detected: source audit before full Claim 5 collection.
- Change: add a secondary evaluation of the released Pendulum ARS checkpoint
  that resets through the complete VecEnv chain.
- Reason: the author's primary evaluation resets the innermost environment
  directly, so its first observation bypasses `VecNormalize`.
- Effect on interpretation: the author-exact buggy protocol remains the
  preregistered primary comparison. The corrected protocol is labeled as a
  sensitivity analysis and cannot replace the headline result.

## D-004 — canonical table filename

- Detected: deterministic table-builder implementation.
- Change: use `summaries.csv` rather than the singular `summary.csv` listed in
  the planned-output section of `SPEC.md`.
- Reason: the table contains multiple summary grains and the plural form
  aligns with the other table names.
- Effect on interpretation: naming only. Row grain and aggregation rules are
  declared in the canonical manifest.

## D-005 — runner provenance

- Detected: pre-HF-Job release review.
- Change: add the runner's own SHA-256 and resolved path to every raw manifest.
- Reason: the HF Jobs CLI uploads the local PEP 723 script separately from the
  mounted input bundle.
- Effect on interpretation: none; this strengthens traceability.

## D-006 — ephemeral TensorBoard scratch path

- Detected: first Claims 1–3 HF Job attempt.
- Change: write TensorBoard event files and RL-Zoo monitor scratch files to a
  disjoint local `/tmp` tree instead of the mounted evidence Bucket.
- Reason: one concurrent TensorBoard writer received `FileNotFoundError` from
  the Bucket's FUSE/object-storage layer even though the directory had been
  created. The structured training metrics, captured worker stdout, and policy
  coefficients were already written separately as canonical evidence.
- Effect on interpretation: none. TensorBoard files are transient transport
  artifacts; all analysis inputs remain append-only in the Bucket. The failed
  Job and its error manifest are retained under their original batch id.