[vtkusers] Could not find extension loader. Extensions disabled.

[Dominik Szczerba]

Hi,

Building vtk 5.8.0 on Ubuntu 12.04 64 bit with an NVIDIA card:

cmake -DCMAKE_BUILD_TYPE=RELEASE -DBUILD_TESTING=OFF
-DBUILD_SHARED_LIBS=ON -DVTK_USE_TK=OFF -DVTK_WRAP_PYTHON=ON
-DVTK_USE_SYSTEM_HDF5=ON $HOME/pack/vtk-5.8.0

I get this message:

"Could not find extension loader.  Extensions disabled."

The error is emitted by Rendering/CMakeLists.txt:

       CHECK_FUNCTION_EXISTS(glXGetProcAddress VTK_USE_GLX_GET_PROC_ADDRESS)
        IF (NOT VTK_USE_GLX_GET_PROC_ADDRESS)
          #         SET(VTK_USE_VTK_DYNAMIC_LOADER 1)
          MESSAGE(STATUS "Could not find extension loader.  Extensions
disabled.")
          SET(VTK_NO_EXTENSION_LOADING 1)
        ENDIF (NOT VTK_USE_GLX_GET_PROC_ADDRESS)

There are thousand instances of this message in google, but I do not
get through with anything conclusive. Some post was arguing that
glXGetProcAddress need not actually be exported at all according to
the standard, but I would not engage in a discussion. In any case, I
do have all my dev packages of x11, nvidia, gl, glu etc. that I know I
need. Is this a bug or am I still missing some package that I can not
identify?

Thanks
Dominik