Annotation processor fails on subcommands with mixins (4.0.0)

[MortronMeymo]

The annotation processor fails with a duplicate option exception when a subcommand uses a mixin.
Minimal example:

import picocli.CommandLine;

class Mixin {
    @CommandLine.Option(names = {"--some-option"})
    public String someOption;
}

@CommandLine.Command(name = "SubCommand")
class SubCommand {
    @CommandLine.Mixin
    public Mixin someMixin;
}

@CommandLine.Command(name = "Command", subcommands = {SubCommand.class})
class Command {
}

Annotation processor output:

error: FATAL ERROR: picocli.CommandLine$DuplicateOptionAnnotationsException: Option name '--some-option' is used by both field String Mixin.someOption and field String Mixin.someOption
        at picocli.CommandLine$DuplicateOptionAnnotationsException.create(CommandLine.java:15020)
        at picocli.CommandLine$DuplicateOptionAnnotationsException.access$1700(CommandLine.java:15014)
        at picocli.CommandLine$Model$CommandSpec.addOption(CommandLine.java:5381)
        at picocli.CommandLine$Model$CommandSpec.addMixin(CommandLine.java:5560)
        at picocli.codegen.annotation.processing.AbstractCommandSpecProcessor$MixinInfo.addMixin(AbstractCommandSpecProcessor.java:896)
        at picocli.codegen.annotation.processing.AbstractCommandSpecProcessor$Context.connectModel(AbstractCommandSpecProcessor.java:851)
        at picocli.codegen.annotation.processing.AbstractCommandSpecProcessor$Context.access$000(AbstractCommandSpecProcessor.java:754)
        at picocli.codegen.annotation.processing.AbstractCommandSpecProcessor.tryProcess(AbstractCommandSpecProcessor.java:162)
        at picocli.codegen.annotation.processing.AbstractCommandSpecProcessor.process(AbstractCommandSpecProcessor.java:133)
        at org.gradle.api.internal.tasks.compile.processing.DelegatingProcessor.process(DelegatingProcessor.java:62)
        at org.gradle.api.internal.tasks.compile.processing.NonIncrementalProcessor.process(NonIncrementalProcessor.java:45)
        at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:972)
 ...

[remkop]

Thank you for the bug report! Investigating...

[remkop]

I found the cause. Basically, mixins are discovered twice and stored in an internal datastructure twice. There is a de-duplication step missing which results in the mixins being added twice, giving the error you are seeing. I'll fix this as soon as possible.

[remkop]

I pushed a fix for this issue to master.
Please verify.

[MortronMeymo]

Verified. The processor now runs fine on this example as well as my real project.

All I need now is for it to generate Java code and then I'm 100% happy :)

[remkop]

Thanks for the verification!

About code generation: I did some initial work on this, which is currently just used for testing (see the test I added in the commit to fix this bug). One of the goals is to be able to run without reflection (#539). That will take a while longer. :-)

[remkop]

I released picocli 4.0.1 with the fix for this bug: https://github.com/remkop/picocli/releases/tag/v4.0.1
Thanks again for the bug report!

[remkop]

...and don’t be shy to star picocli on GitHub and tell your friends if you like the project! :-P