P36a: WAL bucket remotes — objio leaf crate + BucketTransport (sc+wal://, sc+s3://) - #126
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…t asserts (P36a review) Advisor review of Task 5 caught: staged objects were dropped from the RefCell before upload, so a transient bucket failure lost them silently instead of leaving them for a retry; bucket_transport.rs wasn't rustfmt-clean; and the three new tests were missing the !broot.exists() cleanup assertion the read-half tests already use.
…review) pending_packs was only cleared on update_ref's success paths, so a call that failed (NonFastForward or CAS exhaustion) left its uploaded pack hashes in the field. A later, unrelated update_ref on the same long-lived transport (wire::serve keeps one instance per session) then committed a log entry citing a pack it never actually needed, violating the WAL's per-entry "packs support these ref updates" invariant. Fix: take pending_packs out of the shared field into a call-local Vec at the top of update_ref. It survives that call's internal CAS retries (unchanged) but is simply dropped on every exit — success or failure — instead of being explicitly cleared only on success. The abandoned pack itself stays in the bucket as inert, content-addressed orphan garbage, which is correct (compaction is a later phase). Adds a regression test that stages a pack, fails NonFastForward with it pending, then succeeds an update_ref for an unrelated branch on the same instance, and decodes the committed log entry straight from the bucket to assert it references only its own pack.
…OADMAP/THREAT-MODEL for P36a
…uracy, bucket ciphertext pin (P36a)
… h2 0.3 + rustls-webpki 0.101 tree)
tonibergholm-codento
approved these changes
Aug 26, 2026
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Summary
First slice of P36 (spec:
docs/superpowers/specs/2026-08-26-wal-bucket-backend-design.md, ADR-0046): an S3-compatible bucket — or a local directory standing in for one — becomes an sc remote. Immutable content-addressed packs + a parent-linked log + one compare-and-swapped manifest are the entire coordination model: no server, no database, no leader.objio(quarantines the S3 SDK exactly liketlsioquarantines rustls):Buckettrait (conditional get / create-only put / CAS put),DirBucket(local, tests/demos),S3Bucket(aws-sdk-s3 behind a sync facade; credentials via the SDK's standard chain — sc gains no credential surface).walfmtversioned strict codec (manifest + log entries; fail-closed on unknown versions, every length capped).BucketTransportimplements the existingTransporttrait, soclone/fetch/pushwork through the untouchedsync.rsentry points;sc remote add origin sc+s3://bucket/prefix(orsc+wal://<dir>). Readers trust only the parent chain from the CAS'd manifest — orphan/crash debris is invisible. Partial-clonefilteris refused loudly.scl_core::pack::read_object_at_bounded(trusted local path stays unbounded per ADR-0039's carve-out);MAX_OBJECT_SIZEcaps on all WAL metadata; ref-name validation on log contents.Design provenance: the WAL + manifest-CAS coordination layer is borrowed from walgit / Cursor's Continuity design (evaluated in
docs/research/walgit-evaluation.md); sc keeps its end-to-end sealing, which that model lacks.Test plan
cargo test --workspace: 756 passed, 0 failedcargo clippy --workspace --all-targets: cleansc demo --agents 4: zero residue confirmedSC_OBJIO_S3_BUCKET+ MinIO) — not run in CI; first follow-on