Determine variant of dependency

Hi all I'm writing currently a Portfile for an application which depends on port:qt4-mac. Unfortunately, that port has the variant +framework which builds the qt4 libraries as frameworks. Unfortunately this changes the whole build process for my port. Now I would have to determine the variant with which qt4-mac is installed in order to able to build my port. Is there any way I can do that with the means provided by MacPorts? Thanks for the help Michael