configuration / project stage question

[Sándor Norbert]

Hello,

I'm experimenting with DeltaSpike configuration using release 1.8.0, in 
a JBoss EAP6.4 based application.

I have a very simple project:

_META-INF/apache-deltaspike.properties_

   a.Development=dev-a
   a.Production=prod-a
   b=a: ${a}

_CDI bean_

    @Inject
    @ConfigProperty(name = "a")
    private String a;

    @Inject
    @ConfigProperty(name = "b")
    private String b;

    @PostConstruct
    public void initialize() {
        System.out.println(a);
        System.out.println(b);
    }

The project stage is "computed" correctly as Development (I configured 
it using a system property).
But the output is:

   [stdout] dev-a
   [stdout] a: ${a}

So the variable is not resolved. Based on the documentation I would expect:

   [stdout] dev-a
   [stdout] a: dev-a

Am I misunderstand the property resolution process?

Thanks for your help in advance.
Best regards:
Norbi