failure.invalid_covers_nothing: Catch-all covers no rule, because every rule that can break has an arm

Catch-all covers no rule, because every rule that can break has an arm.

Area 4, Failures; not declinable; the next step is usually the agent's.

example

type Quantity = Int {    min: 1    max: 1000}type QuantityTooLarge = Failure {    kind: FailureKind.invalid_value}type QuantityRefused = Failure {    kind: FailureKind.invalid_value}function doubled(quantity: Quantity) fails QuantityTooLarge, QuantityRefused -> Quantity {    var result: Quantity = attempt Quantity(quantity * 2) {        max: QuantityTooLarge        invalid: QuantityRefused    }    return result}

text

error: `invalid:` covers nothing here --> main.jadpo:17:9   |17 |         invalid: QuantityRefused   |         ^^^^^^^ no rule left to cover  reason: Every rule `Quantity(...)` can break has its own arm (`max`), so `invalid:` could never run.  next: Remove `invalid: ...` (agent)  rule: failure.invalid_covers_nothing  help: https://jadpo.dev/docs/errors/failure.invalid_covers_nothingcheck failed: 1 error, 1 file