Hello,

When installing gazebo with ROS repository (with something like sudo apt install ros-kinetic-desktop-full) we got a wrong GAZEBOPLUGINPATH In fact, in /usr/lib/x86_64-linux-gnu/cmake/gazebo/gazebo-config.cmake it is define has

if (GAZEBO_CONFIG_INCLUDED)
  return()
endif()
set(GAZEBO_CONFIG_INCLUDED TRUE)
set(GAZEBO_VERSION 7.0)
set(GAZEBO_MAJOR_VERSION 7)

set(GAZEBO_PLUGIN_PATH "/usr/lib/x86_64-linux-gnu/gazebo-7/plugins")

# The media path contains the location on disk where images,
# materials scripts, shaders, and other related resources are stored.
set(GAZEBO_MEDIA_PATH "/usr/share/gazebo-7/media")

set(GAZEBO_PLUGIN_PATH "/usr/lib/x86_64-linux-gnu/gazebo-7.0/plugins")

# The media path contains the location on disk where images,
# materials scripts, shaders, and other related resources are stored.
set(GAZEBO_MEDIA_PATH "/usr/share/gazebo-7.0/media")

We can see that GAZEBOPLUGINPATH is set twice and the second time wrongly as there is nothing in /usr/lib/x86_64-linux-gnu/gazebo-7.0/plugins. But building new plugin will put them in this directory that is wrong...

If we look at the package from OSRF ( following http://gazebosim.org/tutorials?tut=install_ubuntu ) , the GAZEBOPLUGINPATH is well set :

if (GAZEBO_CONFIG_INCLUDED)
  return()
endif()
set(GAZEBO_CONFIG_INCLUDED TRUE)
set(GAZEBO_VERSION 7.6)
set(GAZEBO_MAJOR_VERSION 7)

set(GAZEBO_PLUGIN_PATH "/usr/lib/x86_64-linux-gnu/gazebo-7/plugins")

# The media path contains the location on disk where images,
# materials scripts, shaders, and other related resources are stored.
set(GAZEBO_MEDIA_PATH "/usr/share/gazebo-7/media")

I don't find where to submit a PR to correct this but the fix should be simple