sudo apt-get install skype:i386
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gnupg-agent : Depends: pinentry-gtk2 but it is not going to be installed or
                        pinentry-curses but it is not going to be installed or
                        pinentry
 libqtcore4:i386 : Depends: libglib2.0-0:i386 (>= 2.22.0) but it is not going to be installed
 skype:i386 : Depends: libqtgui4:i386 (>= 4:4.5.3) but it is not going to be installed
              Recommends: sni-qt:i386 but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.