@Spec must be enclosed in a @Command, or in a class that implements IVersionProvider

[unhit]

Hello, the following piece of code is working with picocli 4.7.6 (with annoation processsor enabled), but breaks in 4.7.7. The goal is to have a reusable ArgGroup with custom header, so I can @Mixin it wherever it's needed. In case my approach was wrong, what's the intended way to achieve it?

Test code:

import picocli.CommandLine;

import java.util.concurrent.Callable;

@CommandLine.Command(name = "main")
class Main implements Callable<Integer> {

    static class Options {
        @CommandLine.Spec
        CommandLine.Model.CommandSpec spec;

        int option1 = 1;
        int option2 = 2;

        @CommandLine.Option(names = "-o1")
        void setOption1(int value) {
            if (value > 10) {
                throw new CommandLine.ParameterException(spec.commandLine(), "option1 must be <= 10");
            }

            this.option1 = value;
        }

        @CommandLine.Option(names = "-o2")
        void setOption2(int value) {
            if (value > 10) {
                throw new CommandLine.ParameterException(spec.commandLine(), "option2 must be <= 10");
            }

            this.option2 = value;
        }
    }

    static class ArgGroup {

        @CommandLine.ArgGroup(exclusive = false, heading = "Shared options%n")
        Options options = new Options();
    }

    @CommandLine.Mixin
    ArgGroup argGroup = new ArgGroup();

    @Override
    public Integer call() throws Exception {
        System.out.printf("Hello world: o1 = %s, o2 = %s%n",
            argGroup.options.option1,
            argGroup.options.option2
        );
        return 0;
    }

    public static void main(String[] args) {
        int exitCode = new CommandLine(new Main())
            .execute(args);
        System.exit(exitCode);
    }

}

Expected output: it works just like in 4.7.6.

Actual output:

java: @Spec must be enclosed in a @Command, or in a class that implements IVersionProvider but was Main.Options: Options

Note that it seems to work at runtime with annotation processor disabled.

Run with: -h
Output:

Unknown option: '-h'
Usage: main [[-o1=<option1>] [-o2=<option2>]]
Shared options
      -o1=<option1>
      -o2=<option2>

Run with: -o1 7 -o2 8
Output:

Hello world: o1 = 7, o2 = 8

Run with: -o1 11 -o2 1
Output:

option1 must be <= 10
Usage: main [[-o1=<option1>] [-o2=<option2>]]
Shared options
      -o1=<option1>
      -o2=<option2>

[remkop]

Yes, that validation is a bit over-enthusiastic. I will remove it in the next release.