Ubuntu 14.04 upgrading Hardware Enablement Stack (HWE) shows unmet dependencies

Solution 1:

I had the exact same problem, and this worked for me:

1. I installed the 14.04 (trusty) versions of those same packages first:

   sudo apt-get install --install-recommends linux-generic-lts-trusty xserver-xorg-lts-trusty libgl1-mesa-glx-lts-trusty libegl1-mesa-drivers-lts-trusty
   

2. Once I installed those, I was able to run the command to upgrade the enablement stack:

   sudo apt-get install --install-recommends linux-generic-lts-utopic xserver-xorg-lts-utopic libgl1-mesa-glx-lts-utopic libegl1-mesa-drivers-lts-utopic
   

3. Lastly, a bit of cleanup:

   sudo apt-get autoremove
   

Edit:

After following the above steps, Steam tried to install a couple packages (libgl1-mesa-dri:i386 and libgl1-mesa-glx:i386) and they were failing. I was able to fix it easily:

sudo apt-get install libgl1-mesa-dri-lts-utopic:i386 libgl1-mesa-glx-lts-utopic:i386

I'll have to remember that pattern for packages in the future if they fail installing/upgrading (try adding -lts-utopic to the package name).