MacPorts 2.1.0: Weird rebuild order of "broken ports" !

[Marko Käning]

Ooops, just now I see that this rebuild order on "sudo port upgrade" is not good:
---
--->  Scanning binaries for linking errors: 100.0%
--->  Found 19 broken file(s), matching files to ports
--->  Found 6 broken port(s), determining rebuild order
--->  Rebuilding in order
    phonon @4.6.0 
    kde4-runtime @4.8.2 
    kdepimlibs4 @4.8.2 
    kmymoney4 @4.6.2 +no_x11
    kdelibs4 @4.8.2 
    strigi @0.7.5 
---
since kdelibs4 is build after kde4-runtime, kdepimlibs4, and kmymoney4, although these ports depend on kdelibs4.

I would have expected to see kdelibs4 build first followed by kde4-runtime, kdepimlibs4 and then kmymoney4.

Why is that?