fixed jsoncpp linking

[flynneva]

No description provided.

[flynneva]

followed this answer to fix the jsoncpp linking issue mentioned in your other PR

[kubja]

Thanks for this. This is for sure the right way to link the shared library. It however doesn't work for me with libjsoncpp-dev package on Ubuntu 20.04, most likely due to the version of the library. I get the following error:

/usr/bin/ld: /home/jakub/3rdparty/new_webrtc_ws/devel/lib/libwebrtc_ros_server.so: undefined reference to `Json::Value::operator=(Json::Value&&)'
/usr/bin/ld: /home/jakub/3rdparty/new_webrtc_ws/devel/lib/libwebrtc_ros_server.so: undefined reference to `Json::Value::operator=(Json::Value const&)'
collect2: error: ld returned 1 exit status

Ubuntu 20.04 comes with 1.7.4-3.1ubuntu2. When I install from source as in the docker file with the latest version (1.9.4), your solution doesn't find the package. What's your version of libjsoncpp?

I think we should ultimately try to figure out why the jsoncpp is not compiled directly with the WebRTC library.

[flynneva]

ive got the same version of libjsoncpp-dev (1.7.4-3.1ubuntu2) as you, and i am on Ubuntu 20.04 - no docker though just normal OS.

it could be because your workstation is a different architecture than mine? (x86_64 is mine, Intel 7i7)

I used sudo apt-get install mlocate and ran locate to find where libjsoncpp is saved:

locate libjsoncpp
/usr/lib/x86_64-linux-gnu/libjsoncpp.a
/usr/lib/x86_64-linux-gnu/libjsoncpp.so
/usr/lib/x86_64-linux-gnu/libjsoncpp.so.1
/usr/lib/x86_64-linux-gnu/libjsoncpp.so.1.7.4