chore(repo): check the wasm target on PRs that touch rust

[FrozenPandaz]

Stacked on #36924 — that PR carries the walker.rs fix this check needs in order to pass. Review this one on top of it; the base will retarget to master once #36924 lands.

Current Behavior

Nothing in PR CI builds or type-checks the wasm target. pnpm build:wasm only runs in publish.yml, so a wasm-only compile break is invisible until publish time — which is exactly how the stray #[cfg] in #36924 escaped review:

error[E0599]: no method named `to_normalized_string` found for reference `&std::path::Path`
  --> packages/nx/src/native/walker.rs:94:40

Expected Behavior

A PR that touches Rust type-checks the native crate for wasm32-wasip1-threads, so the next one of these fails on the PR.

This is an nx task rather than a separate workflow job, so it inherits three things instead of re-implementing them:

• Affected detection. The native named input already covers **/*.rs, **/Cargo.*, the workspace Cargo.toml/Cargo.lock, clippy.toml and .cargo/config.toml — a content-hashed superset of what a paths filter or a git diff | grep gate would match.
• Nx Cloud caching. cache: true with no outputs makes it a pass/fail verdict keyed on those inputs, so an unchanged rerun costs nothing.
• DTE distribution. It joins the existing nx affected sweep and lands on an agent, so it adds no wall clock to main-linux and needs no second runner, checkout, mise, corepack, pnpm store cache or install.

cargo check never links, so it needs none of the wasi-sdk, cmake and sqlite machinery a full pnpm build:wasm does.

Notes

• The script is itself an input. The native named input carries {"runtime": "rustc --version"}, which reports the stable rustc from mise.toml — without the script in inputs, changing the pinned nightly would not invalidate the cache.
• parallelism: false, since the task may invoke rustup, which is not safe against concurrent writes to the same RUSTUP_HOME.
• The nightly is required, not a preference: packages/nx/src/lib.rs puts wasi_ext behind #![feature], which stable rejects with E0554 before it type-checks anything.
• Dispatch is rustup run <toolchain> rather than RUSTUP_TOOLCHAIN, because mise puts its own non-shim cargo on PATH (the rust pin in mise.toml) and that one ignores the variable.
• The toolchain install is conditional, and lands under ~/.rustup on contributor machines. It does not change the active or default toolchain — rustup toolchain install only unpacks, rustup run scopes to one child process, and rust-toolchain.toml pins 1.95.0 inside the repo regardless.

Verification

Run against the stray-#[cfg] code, the task reproduces the E0599 above; with #36924's fix applied it passes. So it is real coverage rather than a check that cannot fail.

Related Issue(s)

None.

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View your CI Pipeline Execution ↗ for commit e76f4af

Command	Status	Duration	Result
nx affected --targets=lint,oxlint,test,build,e2...	✅ Succeeded	7m 8s	View ↗
nx run-many -t check-imports check-lock-files c...	✅ Succeeded	4s	View ↗
nx-cloud record -- pnpm nx-cloud conformance:check	✅ Succeeded	1m	View ↗
nx build workspace-plugin	✅ Succeeded	<1s	View ↗
nx-cloud record -- nx sync:check	✅ Succeeded	19s	View ↗
nx-cloud record -- nx format:check	✅ Succeeded	<1s	View ↗

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☁️ Nx Cloud last updated this comment at 2026-09-05 06:01:38 UTC

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