undefined reference to `ros::init error with catkin_make_isolated

edit

Hi,

I am trying to build the ros packages here. I am using catkin_make_isolated to build the workspace because of the existence of a non catkin package in the workspace. While all the other packages are built successfully, building of the package open3d_conversions_examples throwing the following error. Only a portion of the error is given below.

/usr/bin/ld: CMakeFiles/ex_statistical_outlier_removal.dir/src/ex_statistical_outlier_removal.cpp.o: in function `main':
ex_statistical_outlier_removal.cpp:(.text+0x95): undefined reference to `ros::init(int&, char**, std::string const&, unsigned int)'
/usr/bin/ld: ex_statistical_outlier_removal.cpp:(.text+0x127): undefined reference to `ros::NodeHandle::NodeHandle(std::string const&, std::map<std::string, std::string, std::less<std::string>, std::allocator<std::pair<std::string const, std::string> > > const&)'
/usr/bin/ld: ex_statistical_outlier_removal.cpp:(.text+0x1d6): undefined reference to `ros::NodeHandle::NodeHandle(std::string const&, std::map<std::string, std::string, std::less<std::string>, std::allocator<std::pair<std::string const, std::string> > > const&)'
/usr/bin/ld: CMakeFiles/ex_statistical_outlier_removal.dir/src/ex_statistical_outlier_removal.cpp.o: in function  SubscribeFilterPublish::SubscribeFilterPublish(ros::NodeHandle&, ros::NodeHandle&)':

To me it looks like it is related to roscpp but could not figure out how to eliminate the build error. I tried the solutions proposed in here and here. But none of them worked for me.

Any suggestions to solve this problem will be very helpful.

Regards,

Anirban