CMAKE RPATH not working - could not find shared object file

Question

I am trying to get rid of setting LD_LIBRARY_PATH everytime time I run my program. After adding in the library and targeting my executable to the library, when I run it tells me it can not open shared object library, no such file or directory.

In my CMakeLists.txt I have:

add_library(heart SHARED ${HEART_FILES})
add_executable(run ${RUN_FILES})
target_link_libraries(run heart)
set(CMAKE_SKIP_BUILD_PATH FALSE)
set(CMAKE_BUILD_WITH_INSTALL_RPATH FALSE)
set(CMAKE_INSTALL_RPATH "~/person/target/usr/local/lib")
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)

I set an absolute link to my library folder to test out whether this would create an rpath to my library and it seems like there isn't. I have checked and made sure that the shared library is indeed in lib. libheart.so is the file that is being linked. What else am I missing?

Answer 1

It is because you build heart and run from the same cmake project:

CMAKE_INSTALL_RPATH_USE_LINK_PATH is an interesting and very useful option. When building a target with RPATH, CMake determines the RPATH by using the directories of all libraries to which this target links. Some of these libraries may be located in the same build tree, e.g. libbar.so, these directories are also added to the RPATH. If this option is enabled, all these directories except those which are also in the build tree will be added to the install RPATH automatically. The only directories which may then still be missing from the RPATH are the directories where the libraries from the same project (i.e. libbar.so) are installed to. If the install directory for the libraries is not one of the systems default library directories, you have to add this directory yourself to the install RPATH by setting CMAKE_INSTALL_RPATH accordingly

You can try this:

SET(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")

More documentation here cmake rpath handling

EDIT:

Only this should work:

set(CMAKE_VERBOSE_MAKEFILE ON)
set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)

add_library(heart SHARED ${HEART_FILES})
add_executable(run ${RUN_FILES})
target_link_libraries(run heart)

install(
  TARGETS heart run
  RUNTIME DESTINATION bin
  LIBRARY DESTINATION lib
)

Clean your build directory and then:

cmake -G "Unix Makefiles" -DCMAKE_INSTALL_PREFIX=/home/person/target/usr/local ..
make install

At the end of the g++ line Linking CXX executable run you should see like -Wl,-rpath,/home/person/target/usr/local/lib

If you want a fully relocatable package:

set(CMAKE_INSTALL_RPATH "$ORIGIN/../lib")

PS: are you sur that it is libheart.so that is not found ?

Answer 2

In your CMake file, set the RPATH before defining the targets. The CMAKE_INSTALL_RPATH must be defined before calling add_executable(), otherwise it has no effect.