Undefined reference error while building

[zippyzoo77]

I am trying to update my version of rtabmap to the current one on Ubuntu 20.04 with ros noetic. While following the instructions below from here:
############ rtabmap ###########
$ cd rtabmap
$ git pull origin master
$ cd build
$ make #<-- This is where I get the error
$ make install # Do "sudo make install" if you installed rtabmap in "/usr/local"

############ rtabmap_ros###########
$ roscd rtabmap_ros
$ git pull origin master
$ roscd
$ cd ..
$ catkin_make -j1 --pkg rtabmap_ros

At the indicated point, I end up with the following error:
(base) zippyzoo77@MountainLion:~/rtabmap/build$ make
[ 4%] Built target rtabmap_utilite
[ 5%] Built target res_tool
[ 42%] Built target rtabmap_core
[ 80%] Built target rtabmap_gui
[ 81%] Linking CXX executable ../../bin/rtabmap
/usr/bin/ld: ../../bin/librtabmap_core.so.0.20.19: undefined reference to `octomath::Pose6D::Pose6D(octomath::Pose6D const&)'
collect2: error: ld returned 1 exit status
make[2]: *** [app/src/CMakeFiles/rtabmap.dir/build.make:243: bin/rtabmap] Error 1
make[1]: *** [CMakeFiles/Makefile2:993: app/src/CMakeFiles/rtabmap.dir/all] Error 2
make: *** [Makefile:152: all] Error 2

I have done all the proper steps and have octomap installed, so I really don't know what could be causing this error. Any help on debugging this so I can get rtabmap up and working would be greatly appreciated. Thanks!

[matlabbe]

Which OctoMap version have you installed? ros-noetic-octomap?

[matlabbe]

Cross-ref: https://answers.ros.org/question/398338/undefined-reference-error-while-building/?answer=398587#post-id-398587

[matlabbe]

On Noetic, another cause is that both liboctomap-dev and ros-noetic-octomap may be installed at the same time (some ros packages depend on the system version, and others on the noetic version). Cleanup rtabmap's build directory, make sure you sourced /opt/ros/noetic/setup.bash and redo cmake/make. Rtabmap's cmake should find the version in /opt/ros/noetic first, thus it will work with ros-noetic-octomap-msgs used by rtabmap_ros, and the undefined reference error won't show up.