Oops. You are on the right track with your suggestion, however, since I only added the 
Indigo repository last friday, it is a little different. I came from Ubuntu Precise with 
ROS hydro and still had the precise version of the 'sdformat' package installed which 
conflicts with the newer libsdformat1 package.

Uninstalling sdformat~precise fixes the issue.

Thanks for the help!

Cheers,

Egbert





On Sunday, July 27, 2014 10:55:01 AM Dirk Thomas wrote:
> Hi Egbert,
> 
> there is no ROS packaged sdformat in Indigo anymore.
> This has been resolved weeks ago
> (https://github.com/ros/rosdistro/issues/4633).
> 
> You might still have the package "ros-indigo-sdformat" installed which
> does not exist in the repos anymore.
> You want want to try removing that from your system - then the
> sdformat packages from the Ubuntu repo should install fine.
> 
> Cheers,
> - Dirk
> 
> On Sun, Jul 27, 2014 at 2:54 AM, Egbert van der Wal <ros@pointpro.nl> wrote:
> > Hi,
> > 
> > 
> > 
> > I've attempted to upgrade from ROS Hydro to ROS Indigo after upgrading my
> > Ubuntu Precise to Ubuntu Trusty. However, I'm getting conflicts after
> > 
> > installing ros-indigo-desktop-full.
> > 
> > 
> > 
> > Quick summary:
> > 
> > 
> > 
> > $ apt-get -f install
> > 
> > The following NEW packages will be installed:
> > 
> > libsdformat-dev{a} libsdformat1{a}
> > 
> > The following partially installed packages will be configured:
> > 
> > gazebo2 ros-indigo-desktop-full ros-indigo-gazebo-plugins
> > ros-indigo-gazebo-ros ros-indigo-gazebo-ros-pkgs ros-indigo-simulators
> > 
> > 
> > 
> > 
> > 
> > eggie@Idefix:~$ sudo apt-get -f install
> > 
> > 
> > 
> > Preparing to unpack .../libsdformat1_1.4.11-1ubuntu0.1_amd64.deb ...
> > 
> > Unpacking libsdformat1:amd64 (1.4.11-1ubuntu0.1) ...
> > 
> > dpkg: error processing archive
> > /var/cache/apt/archives/libsdformat1_1.4.11-1ubuntu0.1_amd64.deb
> > (--unpack):
> > 
> > trying to overwrite '/usr/share/sdformat/1.4/projector.sdf', which is also
> > in package sdformat 1.4.11-1~precise
> > 
> > dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
> > 
> > Preparing to unpack .../libsdformat-dev_1.4.11-1ubuntu0.1_amd64.deb ...
> > 
> > Unpacking libsdformat-dev:amd64 (1.4.11-1ubuntu0.1) ...
> > 
> > dpkg: error processing archive
> > /var/cache/apt/archives/libsdformat-dev_1.4.11-1ubuntu0.1_amd64.deb
> > (--unpack):
> > 
> > trying to overwrite '/usr/include/sdformat-1.4/sdf/SDFImpl.hh', which is
> > also in package sdformat 1.4.11-1~precise
> > 
> > Errors were encountered while processing:
> > 
> > /var/cache/apt/archives/libsdformat1_1.4.11-1ubuntu0.1_amd64.deb
> > 
> > /var/cache/apt/archives/libsdformat-dev_1.4.11-1ubuntu0.1_amd64.deb
> > 
> > E: Sub-process /usr/bin/dpkg returned an error code (1)
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > libsdformat-dev and libsdformat1 seem to conflict:
> > 
> > 
> > 
> > 
> > 
> > The relevant versions:
> > 
> > 
> > 
> > $ apt-cache policy libsdformat-dev
> > 
> > libsdformat-dev: