Following this guide on Ubuntu 14.04 (Trusty) using ROS Indigo.

The guide is incomplete, I believe, as after

cd src
git clone https://github.com/roboticsgroup/roboticsgroup_gazebo_plugins.git
git clone https://github.com/pal-robotics/pal_msgs.git
git clone https://github.com/pal-robotics/pal_gazebo_plugins.git
cd ..
catkin_make

I had missing packages, namely, humanoid-nav-msg and ddynamic_reconfigure. Regarding, ddynamic_reconfigure a package exists for deb named ros-indigo-ddynamic-reconfigure-python - installing this package did not remove the error message after catkin_make, which will still complain that the ddynamic pkg is not found. After renaming the package.xml in ddynamic_reconfigure_python to match what the build was looking for, some progress (?) was made...

Next, the build returned the following error

CMake Error at roboticsgroup_gazebo_plugins/CMakeLists.txt:5 (cmake_policy):
Policy "CMP0054" is not known to this version of CMake.

Bypassing this policy the build spits out another error, namely:

[  0%] Building CXX object pal_gazebo_plugins/CMakeFiles/gazebo_harness.dir/src/gazebo_harness.cpp.o
/home/osboxes/catkin_ws/src/pal_gazebo_plugins/src/gazebo_attachment.cpp:9:28: fatal error: ignition/math.hh: No such file or directory
 #include <ignition/math.hh>

Through a naive, brute force, approach, I installed a few libignition-math packages through apt which gave rise to the largest error output of all, of which a snippet is displayed here for your enjoyment:

[  0%] Building CXX object pal_gazebo_plugins/CMakeFiles/gazebo_attachment.dir/src/gazebo_attachment.cpp.o
[  0%] Built target _pal_navigation_msgs_generate_messages_check_deps_TabletPOI
[  0%] Building CXX object pal_gazebo_plugins/CMakeFiles/gazebo_harness.dir/src/gazebo_harness.cpp.o
In file included from /home/osboxes/catkin_ws/src/pal_gazebo_plugins/src/gazebo_attachment.cpp:8:0:
/home/osboxes/catkin_ws/src/pal_gazebo_plugins/include/pal_gazebo_plugins/gazebo_attachment.h:49:3: error: ‘ignition’ does not name a type
   ignition::math::Pose3d pose_;
   ^
/home/osboxes/catkin_ws/src/pal_gazebo_plugins/src/gazebo_attachment.cpp: In member function ‘virtual void gazebo::GazeboAttachment::Load(gazebo::physics::ModelPtr, sdf::ElementPtr)’:
/home/osboxes/catkin_ws/src/pal_gazebo_plugins/src/gazebo_attachment.cpp:52:11: error: ‘class gazebo::GazeboAttachment’ has no member named ‘pose_’
     this->pose_ = _sdf->Get<ignition::math::Pose3d>("pose");
           ^

I've been at this for a full day... Does anybody have any ideas? They're all welcome and appreciated.