SwiftLint: how to configure rule severity for a rule with warning and error configurations

Question

I would like to configure the Swiftlint cyclomatic_complexity rule to always have the severity level of warning.

Here are the approaches I have tried in the .swiftlint.yml.

cyclomatic_complexity: warning

cyclomatic_complexity: 
  severity: warning

Both of these yield the same result. Namely, upon running swiftlint, before linting it prints the following error.

Invalid configuration for 'cyclomatic_complexity'. Falling back to default.

How do you configure the severity of this rule for swiftlint, so that it only generates warnings and not errors?

Answer 1

# .swiftlint.yml
cyclomatic_complexity: 20