[CMake] Weirdness with shared library, RPATH policy on MacOS

[Martin Costabel]

Chris Wolf wrote:
[]
> Have you actually built shared libraries on MacOS with CMake?  If so, maybe an example
> of yours would be more helpful.

The following settings work for me when building vtk5.6 for Fink:

   -DCMAKE_INSTALL_NAME_DIR:STRING=/sw/lib/vtk56 \
   -DCMAKE_BUILD_WITH_INSTALL_RPATH:BOOL=ON \
   -DCMAKE_INSTALL_RPATH:STRING="${CMAKE_INSTALL_NAME_DIR}" \
   -DVTK_USE_RPATH=ON

In this case, during build time, that is before running make, one needs 
to set something like

   export DYLD_LIBRARY_PATH=`pwd`/bin

so that the newly built libraries are found in the build tree, otherwise 
the executables look for them in the install directory.

In principle, a second method using

   CMAKE_BUILD_WITH_INSTALL_RPATH=OFF

should also be possible, in which case cmake should use the BUILD_RPATH 
during building and then, at installation time, use install_name_tool to 
change all RPATHs to their INSTALL value. In the case of VTK, this works 
for the dylibs and for some of the executables, but not for python 
modules. Therefore I prefer the first method where the RPATH is 
immediately set to its INSTALL value, both in the dylibs and, by 
inheritance, in the executables.

-- 
Martin