build: return to released wit-bindgen after cancellation fixes ship #720

Current status — Parked: blocked on upstream wasip3/wit-bindgen compatibility (2026-10-23)

Next scheduled review: 2026-11-12. Recheck the first published compatible wasip3 + wit-bindgen combination, rather than automatically migrating on the review date.

Do not migrate yet. Although released upstream wit-bindgen v0.63.0 contains both required cancellation fixes (#1740 and #1743), Wetware's native P3 guests also use wasip3 0.9.0, which requires wit-bindgen ^0.62.0. A direct move to 0.63.0 is not a safe isolated dependency bump.

Implementation attempt / evidence (2026-10-23)

• Conductor's isolated reproduction: replacing the direct pin with wit-bindgen 0.63.0 fails with Rust E0308 due to incompatible StreamReader types; identical source passes using the current Wetware fork. An independent adversarial reviewer confirmed the compatibility blocker. The reproduction notes are in the local Conductor workspace: .context/720-blocker/README.md (not uploaded here).
• The latest inspected upstream bytecodealliance/wasi-rs crates/wasip3/Cargo.toml declares wasip3 0.9.1+wasi-0.3.2, but its root Cargo.toml still declares wit-bindgen = 0.62.0. Upstream wasi-rs #171 (merged 2026-10-19) explicitly says the 0.9.1 bindings were regenerated with wit-bindgen 0.62.0. Therefore moving from wasip3 0.9.0 to 0.9.1 does not establish compatibility with 0.63.0.
• The cancellation audit also found missing explicit test coverage for spawned-task survival after root cancellation. Cancellation behavior with 0.63.0 has not been validated in Wetware.
• No tracked files were changed; no commit, PR, merge or full CI run occurred.

Scheduling: Parked / blocked on upstream compatibility; next review 2026-11-12. Do not treat the issue as Ready. Retain the current reviewed fork until a compatible, released wasip3/wit-bindgen combination is demonstrated. Do not mix in a speculative API adapter, fork of wasip3, or weakened P3 cancellation semantics solely to retire the fork.

Wake conditions

1. A released upstream wasip3 supports wit-bindgen 0.63.0 or later with equivalent cancellation semantics, and the native P3 guest compilation/reproduction succeeds.
2. Upstream publishes an endorsed compatibility path with convincing test evidence.
3. A concrete security/reliability problem with the existing fork changes the risk decision.

When unblocked: inventory every independent guest manifest/lockfile, regenerate via Cargo, migrate provenance/docs, add the missing root-versus-spawned-task cancellation regression, run targeted native P3 and RPC/stream/teardown tests, workspace checks and CI, and independently review the full diff. Close only after a validated merge.

Previously verified prerequisite: wit-bindgen v0.63.0 contains #1740 and #1743, confirmed by release-tag ancestry. This solves only the wit-bindgen release gate, not the end-to-end dependency compatibility gate.

Context

Wetware currently pins a temporary Wetware wit-bindgen fork because of an async cancellation/runtime bug.

Verified against wetware/ww master commit a96e53802595e78d4459dca6ec0eac6acacc9f21 on 2026-10-14:

• package: wit-bindgen 0.62.0
• repository: https://github.com/wetware/wit-bindgen
• revision: 025f95c294373c73e12eaee335577c81477d5a20
• Cargo.lock resolves the wit-bindgen 0.62.0 package family to the same revision

Two related upstream fixes are now merged.

#1740 — cancelled-task wake state

bytecodealliance/wit-bindgen#1740

Title:

rust: suppress wake notifications while destroying async tasks

Status:

Merged upstream

Merge commit:

1145d464309219e2f2d8857507413cb41d8c1ca5

This fixes destruction-time wake notifications after a component task has been cancelled.

#1743 — spawned tasks survive root cancellation

bytecodealliance/wit-bindgen#1743

Title:

Don't cancel spawned rust tasks on component task cancel

Status:

Merged upstream

Merge commit:

1559c82dc3e8f8fa7dfd0efd2665a82ca4b94717

This is the follow-up bug Alex Crichton identified during review of #1740. It changes EVENT_CANCEL semantics so cancellation applies to the component task's root computation while Rust tasks created with wit_bindgen::spawn_local continue running to completion.

#1743 is based directly on the #1740 merge. GitHub's commit comparison shows the #1740 merge as the merge base and #1743 two commits ahead, so upstream main now contains both fixes in sequence.

Historical note from the 2026-10-13 investigation (superseded by the current status above): At tracker update time, the latest released wit-bindgen version is v0.62.0, published on 2026-09-10. The release tag resolves to c604ee01c03f50d7301984a3c920a650752cd136. GitHub's commit comparisons show that tag is 21 commits behind the #1740 merge and 23 commits behind the #1743 merge. It contains neither fix, so no released upstream version currently satisfies this tracker.

Desired outcome

Return Wetware from the temporary fork pin to a normal released upstream wit-bindgen containing both #1740 and #1743.

There is no unresolved spawn_local watch item remaining from this investigation: the follow-up issue identified during #1740 review is #1743 and is already fixed upstream.

Both upstream PRs being merged is not sufficient to complete this tracker.

This follows the same dependency-return lifecycle as #717, but neither issue depends on the other:

upstream fixes merged
        ↓
wait for suitable released version containing both
        ↓
return Wetware to normal released dependency
        ↓
remove temporary fork

Scheduling

The upstream release prerequisite is fulfilled. Implement and validate the targeted dependency return above; do not wait for the historical check-up date. Keep the issue open pending merged implementation and final regression evidence.

Exit criteria

• Identify the first suitable released upstream wit-bindgen containing both #1740 and #1743.
• Update Wetware from the temporary fork/git pin to the released dependency.
• Run the relevant guest cancellation / async runtime regressions.
• Verify the corrected root-vs-spawned-task cancellation behavior where relevant.
• Remove obsolete fork/provenance configuration and documentation.
• Verify no wetware/wit-bindgen pin remains solely for these fixes.

#1740 + #1743 merged != tracker complete.

released upstream dependency adopted by Wetware = tracker complete.