Failure to find libgpgme.so while building rosbag_storage
I'm building on FreeBSD from source, using catkin_make_isolated.
When I'm building rosbag_storage the linker fails to find libgpgme.so with the error ld: cannot find -lgpgme.
I have installed the libgpgme package and confirm libgpgme.so is in /usr/local/lib. Apparently, this is not a default search path (on FreeBSD only?) for libraries to link, however.
I added link_directories(/usr/local/lib) at the top of the CMakeList.txt file for rosbag_storage. The linker now finds the library and rosbag_storage builds just fine.
Is there a better way to do this than to modify the CMakeList.txt? I'm trying to keep the FreeBSD build process as close as possible to the Ubuntu process, so the fewer manual modifications I have to make, the better.
As much as you're encountering this while building a ROS package, I don't believe this is a ROS problem necessarily, but more a general CMake how-to-link-a-library problem (but the specifically with
libgpgme).Could you try creating an MWE which just tries to link
libgpgmeto a test program? If that also doesn't work, it would seem to be a general issue.It does appear to be a general issue with FreeBSD not automatically including
/usr/local/lib.My question, more specifically, is whether there is a way for me to specify link directories at build time so I don't have to modify the
CMakeList.txtfile.I suppose this is a
catkinquestion...?No. That would make it a CMake one. Catkin doesn't do anything with this. And I guess the keyword would be: specify a library search path. Not link directories (as that is the name of the CMake command).
I'm new to cmake (and catkin), so I'm having a hard time either understanding or implementing your response.
For
rosbag_storage, theCMakeList.txtfile includes the following:set(AES_ENCRYPT_LIBRARIES "crypto" "gpgme")The variable is then used as follows:
target_link_libraries(rosbag_storage ... ${AES_ENCRYPT_LIBRARIES})I cannot find a command line argument to pass to cmake (via catkin_make) to allow the linker to find
libgpgme. I continue to get the errorld: cannot find -lgpgme.The only thing I've found that works is to place
link_directories(/usr/local/lib)inCMakeList.txtbeforeset(AES_ENCRYPT_LIBRARIES "crypto" "gpgme").I can limit the superfluity of this with a check for the target OS:
if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD") link_directories(/usr/local/lib) endif()