"SwiftVersionChecker: Toolchain Drift, Caught Early"

swift-tools-version validation and upgrade feasibility — because “works on my machine” often means “works on my toolchain.”

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Swift toolchains drift. Your laptop is on 6.4; the build server is on 6.3.3; CI is on something else again. A Package.swift that declares a swift-tools-version newer than a target machine’s toolchain fails to resolve there — and the failure often looks like a mysterious dependency error rather than “your toolchain is too old.” SwiftVersionChecker validates the declared tools version and assesses whether an upgrade is feasible before that mismatch bites.

Why it matters more than it sounds

I run into this constantly: local Swift 6.4, a production server on 6.3.3, and features that build fine in one place and not the other. The rule of the workflow is to verify version compatibility first, before any deploy — because discovering a toolchain mismatch after you’ve shipped is expensive, and discovering it at commit time is free.

The checker keeps the declared swift-tools-version honest against what the project actually needs, and flags when a bump is being proposed that a target environment can’t yet support. It’s a small guardrail against a specific, recurring source of “it built for me” — the kind of drift that’s invisible until the one machine that matters can’t resolve the package.

Try it

quality-gate --check swift-version

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Source: github.com/jpurnell/quality-gate-swift