mark@homestar:~$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Failed
The following packages have unmet dependencies.
 gvfs : Depends: gvfs-daemons (>= 1.20.3-0ubuntu1.2)
        Depends: gvfs-daemons (< 1.20.3-0ubuntu1.2.1~)
 indicator-network : Depends: unity8 (>= 7.82) but it is not going to be installed
 libgl1-mesa-dri : Depends: libllvm3.4 but it is not going to be installed
                   Recommends: libtxc-dxtn-s2tc0 but it is not going to be installed or
                               libtxc-dxtn0
 libgl1-mesa-glx : Depends: libglapi-mesa (= 10.1.3-0ubuntu0.6)
 libstdc++6 : Depends: gcc-4.9-base (= 4.9.2-0ubuntu1~14.04) but 4.9.3-0ubuntu4 is to be installed
 unity-scope-mediascanner2 : Depends: mediascanner2.0 but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
E: Internal error, Upgrade broke stuff