Unable to link after update to 2.24

[kevindehecker]

---

Required Info
Camera Model	D400
Firmware Version	(Open RealSense Viewer --> Click info)
Operating System & Version	Ubuntu 18.04
Kernel Version (Linux Only)	(e.g. 4.15.0.54)
Platform	PC
SDK Version	2.24
Language	C }

Issue Description

After Ubuntu automatically updated librealsense to 2.24, (and rebooting!), I'm unable to link with librealsense.

/usr/bin/ld: cannot find -lrealsense2
collect2: error: ld returned 1 exit status
CMakeFiles/lalala.dir/build.make:503: recipe for target 'lalala' failed
make[2]: *** [lalala] Error 1
CMakeFiles/Makefile2:72: recipe for target 'CMakeFiles/lalala.dir/all' failed
make[1]: *** [CMakeFiles/lalala.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2

Before the update to 2.24 all was fine. Even after updating I could compile, but I tried to reboot because of #4350, after which the problem appeared. Have reproduced this problem on two computers.

[kevindehecker]

I've reverted the packages back to v2.23, this solves the problem for now:

#sudo apt-cache policy  librealsense2 #pick v2.23
sudo apt remove librealsense2*
sudo apt-get install librealsense2=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dev=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dbg=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-gl*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-udev*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-utils=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dkms

[ev-mp]

@kevindehecker hello,
There were a missing dependency in the Debian build that has been resolved. Please try the latest and update

[kevindehecker]

Yes seems to work again, thanks!

[kevindehecker]

Crap, it is not working!

I tumbled into the reboot trap... After a reboot (needed for something else) I could not link once more.
BTW, the reported version after updating is still 2.24.

[ev-mp]

That's correct - the change is in the Debian build (number) - there is no change in Librealsense.
The only thing that changes after reboot is the the source ... and the linker list are being updated.
Is it possible that you have several versions installed in separate locations ?
Can you share the error log ?

[kevindehecker]

Error log? You mean the linker error?

/usr/bin/ld: cannot find -lrealsense2
collect2: error: ld returned 1 exit status
CMakeFiles/lalala.dir/build.make:503: recipe for target 'lalala' failed
make[2]: *** [lalala] Error 1
CMakeFiles/Makefile2:72: recipe for target 'CMakeFiles/lalala.dir/all' failed
make[1]: *** [CMakeFiles/lalala.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2

Really not that helpfull, but I don't have other errors... Please specify.

[kevindehecker]

Aha, found the problem. In my CMakeList.txt I set the realsense library as follows:

set(REALSENSE realsense2) 
target_link_libraries(${PROJECT_NAME} ${REALSENSE})

Probably got that from some example in the early days. However, if I properly find the realsense package, the linker problem is solved!

find_package(realsense2 REQUIRED)
target_link_libraries(${PROJECT_NAME} ${realsense2_LIBRARY})

[danneboom]

Same problem here after 2.24 (2.24.0-0~realsense0.1243) update. Before, in QT I could link with

 LIBS += -lrealsense2

Now, it says

/usr/bin/ld: cannot find -lrealsense2

and also LIBS += -L/usr/lib/x86_64-linux-gnu -lrealsense2 or LIBS+=/usr/lib/x86_64-linux-gnu/librealsense2.so does NOT work. Using pkg-config like

CONFIG+=link_pkgconfig
PKGCONFIG+=realsense2

does not change anything. In CMake though, before 2.24 I was doing

    find_library( REALSENSE_LIBRARY NAMES realsense2 PATHS /usr/local/lib)
    target_link_libraries(myLib ${REALSENSE_LIBRARY} )

That does not work anymore, even with new path /usr/lib//usr/lib/x86_64-linux-gnu! I have to use find_package now.

    find_package( realsense2 REQUIRED)
    include_directories(  ${realsense2_INCLUDE_DIR} )
    target_link_libraries(myLib ${realsense2_LIBRARY} )

But in QT it still fails.

[qihao-huang]

I've reverted the packages back to v2.23, this solves the problem for now:

#sudo apt-cache policy  librealsense2 #pick v2.23
sudo apt remove librealsense2*
sudo apt-get install librealsense2=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dev=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dbg=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-gl*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-udev*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-utils=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dkms

When I try to apt-cache show <package-name>, realsense viersion I find is 2.23.0-0~realsense0.1166=5

Can you test it ?
Thanks.

[qihao-huang]

I've reverted the packages back to v2.23, this solves the problem for now:

#sudo apt-cache policy  librealsense2 #pick v2.23
sudo apt remove librealsense2*
sudo apt-get install librealsense2=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dev=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dbg=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-gl*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-udev*=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-utils=2.23.0-0~realsense0.1166
sudo apt-get install librealsense2-dkms

When I try to apt-cache show <package-name>, realsense viersion I find is 2.23.0-0~realsense0.1166=5

Can you test it ?
Thanks.

add ${realsense2_LIBRARY} to target_link_libraries() solve this bug.