/home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.cc:70:49: error: invalid use of incomplete type ‘class Ogre::RTShader::Program’
   Ogre::RTShader::Function* psMain = psProgram->getEntryPointFunction();
                                                 ^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/OGRE/RTShaderSystem/OgreShaderProgramManager.h:30:0,
                 from /usr/include/OGRE/RTShaderSystem/OgreRTShaderSystem.h:30,
                 from /home/racko/tmp/gazebo/gazebo/rendering/ogre_gazebo.h:67,
                 from /home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.hh:21,
                 from /home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.cc:50:
/usr/include/OGRE/RTShaderSystem/OgreShaderPrerequisites.h:61:7: note: forward declaration of ‘class Ogre::RTShader::Program’
 class Program;
       ^~~~~~~
/home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.cc:73:20: error: invalid use of incomplete type ‘class Ogre::RTShader::Function’
   mVSInPos = vsMain->getParameterBySemantic(vsMain->getInputParameters(),
                    ^~
In file included from /usr/include/OGRE/RTShaderSystem/OgreShaderProgramManager.h:30:0,
                 from /usr/include/OGRE/RTShaderSystem/OgreRTShaderSystem.h:30,
                 from /home/racko/tmp/gazebo/gazebo/rendering/ogre_gazebo.h:67,
                 from /home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.hh:21,
                 from /home/racko/tmp/gazebo/gazebo/rendering/CustomPSSMShadowCameraSetup.cc:50:
/usr/include/OGRE/RTShaderSystem/OgreShaderPrerequisites.h:67:7: note: forward declaration of ‘class Ogre::RTShader::Function’
 class Function;
       ^~~~~~~~