message: Use non-strict parsing when parsing BaseCommand flags
  Otherwise unknown in this context but valid extra flags are not recognized
diff: @@ -66,7 +66,7 @@ export default abstract class BaseCommand extends Command {
  opt.flags = BaseCommand.flags;
  }
  - return Parser.parse(argv, { context: this, ...opt });
  + return Parser.parse(argv, { context: this, ...opt, strict: false });
  }
  public async init() {
  