shelbi msrv-check

shelbi msrv-check [OPTIONS]

shelbi msrv-check builds the Rust workspace in the current directory on the minimum Rust version it declares (the rust-version in Cargo.toml), the way a typical CI msrv job does:

cargo +<rust-version> check --workspace --all-targets --locked

It's meant as a zen.checks.local entry on Rust projects. A stable-toolchain build won't notice a lockfile change that pulls in a dependency needing a newer Rust than the declared minimum; this catches it before handoff instead of only in CI.

It reads rust-version from the nearest Cargo.toml at or above the current directory. If the toolchain isn't installed it installs it once with rustup. It never fails for reasons unrelated to the code:

• no rust-version found, rustup missing, or a toolchain that can't be installed (offline, for example) prints a warning on stderr and exits 0 (a skip);
• a real MSRV break (the check ran and cargo failed) exits with cargo's non-zero status.

msrv-check has no flags of its own beyond the global --root and -p, --project, which it doesn't use.

Examples

Add it to a project's local Zen checks:

zen:
  checks:
    local:
      - shelbi msrv-check

Run it by hand from the repository root:

shelbi msrv-check

See also

• Project configuration: where zen.checks.local is set.
• Zen Mode: when local checks run.