plugin library path issues

[simonschmeisser]

I'm testing my new ubuntu ppa and somehow library paths are still messed up

simon@sisBook:~/proggn/isys/ws$ LANG=c rosrun rviz rviz 
[ INFO] [1609771263.214425856]: rviz version 1.14.4
[ INFO] [1609771263.214476142]: compiled against Qt version 5.15.2
[ INFO] [1609771263.214492089]: compiled against OGRE version 1.12.10 (Rhagorthua)
[ INFO] [1609771263.225121082]: Forcing OpenGl version 0.
terminate called after throwing an instance of 'Ogre::InternalErrorException'
  what():  InternalErrorException: Could not load dynamic library /usr/lib/OGRE/RenderSystem_GL.  System Error: /usr/lib/OGRE/RenderSystem_GL.so.1.12.10: cannot open shared object file: No such file or directory in DynLib::load at /build/ogre-1.12-o5dbVM/ogre-1.12-1.12.10+dfsg1/OgreMain/src/OgreDynLib.cpp (line 113)

the plugins are actually installed at /usr/lib/x86_64-linux-gnu/OGRE/RenderSystem_GL.so.1.12.10

packages can be found here: https://launchpad.net/~s-schmeisser/+archive/ubuntu/ogre-1.12

[paroj]

are you in a folder that contains a plugins.cfg?

I just tried

import Ogre.Bites
ctx = Ogre.Bites.ApplicationContext()
ctx.initApp()

with your package and everything seems to be resolved correctly.

[simonschmeisser]

ah, rviz uses a dummy one: https://github.com/ros-visualization/rviz/blob/melodic-devel/ogre_media/plugins.cfg

and then reconstructs it in code: https://github.com/ros-visualization/rviz/blob/d4603a4f6bd0a0009a049268bfbdc11435dea36f/src/rviz/ogre_helpers/render_system.cpp#L163

where the plugin path is a CMake variable: https://github.com/ros-visualization/rviz/blob/d4603a4f6bd0a0009a049268bfbdc11435dea36f/src/rviz/env_config.cpp.in#L52

which gets read from pkconfig here: https://github.com/ros-visualization/rviz/blob/d4603a4f6bd0a0009a049268bfbdc11435dea36f/CMakeLists.txt#L64

or from CMake:

ogre/CMake/Templates/OGREConfig.cmake.in

Line 27 in 108b6e2

set(OGRE_PLUGIN_DIR "@PACKAGE_CMAKE_INSTALL_PREFIX@/@OGRE_PLUGIN_DIR_CMAKE@")

however there is some strange code in @PACKAGE_INIT@:

####### Expanded from @PACKAGE_INIT@ by configure_package_config_file() #######
####### Any changes to this file will be overwritten by the next CMake run ####
####### The input file was OGREConfig.cmake.in                            ########

get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../../" ABSOLUTE)

# Use original install prefix when loaded through a "/usr move"
# cross-prefix symbolic link such as /lib -> /usr/lib.
get_filename_component(_realCurr "${CMAKE_CURRENT_LIST_DIR}" REALPATH)
get_filename_component(_realOrig "/usr/lib/x86_64-linux-gnu/OGRE/cmake" REALPATH)
if(_realCurr STREQUAL _realOrig)
  set(PACKAGE_PREFIX_DIR "/usr")
endif()
unset(_realOrig)
unset(_realCurr)

macro(set_and_check _var _file)
  set(${_var} "${_file}")
  if(NOT EXISTS "${_file}")
    message(FATAL_ERROR "File or directory ${_file} referenced by variable ${_var} does not exist !")
  endif()
endmacro()

macro(check_required_components _NAME)
  foreach(comp ${${_NAME}_FIND_COMPONENTS})
    if(NOT ${_NAME}_${comp}_FOUND)
      if(${_NAME}_FIND_REQUIRED_${comp})
        set(${_NAME}_FOUND FALSE)
      endif()
    endif()
  endforeach()
endmacro()

####################################################################################

which leads to OGRE_PLUGIN_PATH being set as /usr/lib/OGRE instead of /usr/lib/x86_64-linux-gnu/OGRE/

[paroj]

that code comes from:
https://cmake.org/cmake/help/latest/module/CMakePackageConfigHelpers.html#generating-a-package-configuration-file

which is supposed to make the cmake scripts relocatable. I have no idea though, what is going wrong here..