Pin the CI Rust toolchain - #50
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The action SHA is pinned, but the action's own default toolchain is "stable", so the version CI actually installs floats. Master last ran green in May and was red by September without a single repository change: new clippy lints had landed in the meantime, and the advisory database had moved. The first pull request opened after that inherited three unrelated failures. Pin the toolchain the two jobs install. Bumping it then becomes its own pull request, where the lint delta is visible and reviewable, instead of arriving unannounced on whoever opens the next one. 1.98.0 is the version the workspace is currently verified against: fmt, clippy with -D warnings, test --workspace --locked, and audit all pass on it at 099cff4.
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Included review availability: 2 reviews are currently available. Your included PR review attempts over the past 7 days set your current allowance at 5 reviews per hour. 📝 WalkthroughWalkthroughThe CI workflow pins Rust to ChangesCI toolchain pinning
Estimated code review effort: 1 (Trivial) | ~2 minutes Merge Risk: ⚪ Minimal · up to CI now uses Rust 1.98.0 rather than following stable implicitly, making compiler updates explicit. The change is ready to merge. Poem
🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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Naming an explicit toolchain version makes the action install the minimal profile, where the "stable" default it replaced brought rustfmt and clippy along. The Format step failed immediately with "cargo-fmt is not installed for the toolchain 1.98.0" on both runners. Request the two components by name in the job that runs them. The audit job needs neither, so it stays minimal.
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Inline comments:
In @.github/workflows/ci.yml:
- Around line 32-33: Update the comment in the Rust toolchain setup step to
accurately state that both stable and explicit toolchains use the minimal
profile, and that rustfmt and clippy must be requested because the profile omits
them.
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The action passes --profile minimal for every toolchain, not only for explicit versions, so the previous comment described the mechanism wrongly. The reason this went unnoticed under "stable" is that the runner image already ships that toolchain with rustfmt and clippy present.
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Problem
The workflow pins the action by SHA:
That SHA is a commit on the action's
stablebranch, and itsaction.ymldeclarestoolchainwithdefault: stable. So the action code is pinned but the toolchain it installs is not — CI silently tracks whatever stable is on the day it runs.That is why
masterwas green on 2026-05-06 and red by September without a single repository change: new clippy lints had shipped in the interim, and the advisory database had moved. The next PR opened after that gap (#48) inherited three unrelated failures and needed #49 to clear them before it could be judged on its own merits.Change
Pass an explicit
toolchainto both jobs. Bumping the compiler becomes its own PR where the lint delta is visible, rather than landing unannounced on whoever opens the next one.Why 1.98.0
It is the version the workspace is currently verified against. On
099cff4withrustc 1.98.0 (88d9e12ae 2026-08-18):Trade-off worth naming
A pin trades one failure mode for another: CI stops catching new lints the day they ship, so upstream drift accumulates quietly until someone bumps. That is the intended trade — the drift becomes a reviewable diff in a dedicated PR instead of a surprise on unrelated work — but it only pays off if the bump actually happens periodically. A scheduled reminder or a Dependabot-style bump job would close that loop; this PR deliberately does not add one, since the cadence is your call.
This changes CI only. It adds no
rust-toolchain.toml, so local development is unconstrained and nobody is forced onto a different compiler.🤖 Generated with Claude Code
https://claude.ai/code/session_01EwBDuaQS537MdX3GUtmhqj
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