if you use a system property with a special layout, this will be translated into a project property, ie

$ ./gradlew build -Dorg.gradle.project.myProperty='Hi, world'

I just wonder when one would ever need to do that.. why not using

-PmyProperty='Hi, world'

in the first place?

Its there to account for a wide variety of restrictions that may exist on CI systems - of course, if you can specify any arbitrary command line, you can just use -P; in the case where the execution definition is more structured you may only be able to set system properties (and/or environment variables) and not arbitrary command line arguments. Documented here.

got it, thanks