MGS3005: tool too old

The binary exists, reports a version, and is usable - and that version is older than the spell's ops support.

[MGS3005] golangci-lint v1.9.0 is older than this spell supports (>= 2.0).
The op "golangci-lint" needs a newer one

The fourth question about a tool

Each is distinct, and only the last two used to have answers:

Without a floor, a too-old binary fails with whatever it says about an unrecognized flag - the same misleading failure MGS3004 exists to prevent, one question over.

Declaring one

export fun mgs_getTools() > {str: Tool} {
    return {
        "golangci-lint": Tool{
            probe = Command{bin = "golangci-lint", args = ["--version"]},
            floor = ">= 2.0",
        },
    };
}

The constraint is the same syntax magus.yaml's required_version uses, and a malformed one is a load error rather than a silent pass - a floor nobody can parse protects nobody.

A floor needs a probe: there is nothing to compare without one.

What it deliberately does not do

An unprobeable tool is not "too old." If the probe fails, the floor passes. Failing there would make a floor a second way for a missing tool to break, with a worse message than MGS3003's.

Output magus cannot parse is not "too old" either. A tool whose version line carries no semver is left alone rather than judged against a constraint it was never going to satisfy.

The check runs before the op forks and is memoized per tool and directory, so a declared floor costs one probe per run, not one per target.