#5 Cyclic dependencies in layers

[Pawel Kowalski]

With layers defined in a pespective, it's not possible to
have a graph laid out if there is a cyclic dependency
between nodes from the same layer. This bug doesn't
hinder the tool to have reports generated. Only the
graphical representation is concerned. It's probably a
bug in an external library (dot-tool), try to correct it
there and submit a patch.