When we declare a profile in the settings.xml, it will never be applied to POMs loaded from the Maven repository. This means that overriding the central repository definition - for instance - cannot be done without using mirror definitions, since transitive dependencies (any dependency of a direct dependency) will skip the modified definition and use the original from the super-POM instead.
I'm attaching a testing setup that was originally reported for
MNG-3553, which exhibits this problem when dealing with scope == import. The instructions for using it are as follows: