I installed the latest gnome3 from webupd8's ppas and somehow borked my system.

while doing a ppa-purge it somehow decided to remove the ubuntu-desktop meta package

now while i'm trying to get back to pure ubuntu, i try this:

sudo apt-get install ubuntu-desktop

and get this:

ubuntu-desktop : Depends: eog but it is not going to be installed

              Depends: gnome-control-center but it is not going to be installed

              Depends: gnome-session but it is not going to be installed

              Depends: nautilus but it is not going to be installed

              Depends: nautilus-sendto but it is not going to be installed

              Depends: unity but it is not going to be installed

              Recommends: gnome-screensaver but it is not going to be installed

              Recommends: libgail-3-common but it is not going to be installed

              Recommends: nautilus-share but it is not going to be installed

              Recommends: totem but it is not going to be installed

              Recommends: totem-mozilla but it is not going to be installed

              Recommends: ubuntuone-client-gnome but it is not going to be installed

E: Unable to correct problems, you have held broken packages.

trying to install any of these results in more held dependencies that will not install.

How do i "Unhold the broken packages" to get back to where nautilus can be installed?