Error in launching rtabmap node "symbol lookup error"

[Aman virmani]

Command:
rosrun rtabmap_ros rtabmap

[ INFO] [1606077660.880061127]: Starting node...
[ INFO] [1606077660.902329366]: Initializing nodelet with 12 worker threads.
[ INFO] [1606077660.983383716]: /rtabmap(maps): map_filter_radius          = 0.000000
[ INFO] [1606077660.983424659]: /rtabmap(maps): map_filter_angle           = 30.000000
[ INFO] [1606077660.983452481]: /rtabmap(maps): map_cleanup                = true
[ INFO] [1606077660.983460571]: /rtabmap(maps): map_always_update          = false
[ INFO] [1606077660.983481819]: /rtabmap(maps): map_empty_ray_tracing      = true
[ INFO] [1606077660.983508126]: /rtabmap(maps): cloud_output_voxelized     = true
[ INFO] [1606077660.983514383]: /rtabmap(maps): cloud_subtract_filtering   = false
[ INFO] [1606077660.983522428]: /rtabmap(maps): cloud_subtract_filtering_min_neighbors = 2
[ INFO] [1606077660.983883352]: /rtabmap(maps): octomap_tree_depth         = 16
[ INFO] [1606077660.999909739]: rtabmap: frame_id      = base_link
[ INFO] [1606077660.999952969]: rtabmap: map_frame_id  = map
[ INFO] [1606077660.999962152]: rtabmap: use_action_for_goal  = false
[ INFO] [1606077660.999975322]: rtabmap: tf_delay      = 0.050000
[ INFO] [1606077660.999984609]: rtabmap: tf_tolerance  = 0.100000
[ INFO] [1606077660.999993933]: rtabmap: odom_sensor_sync   = false
[ INFO] [1606077661.271569410]: RTAB-Map detection rate = 1.000000 Hz
[ INFO] [1606077661.271676669]: rtabmap: Using database from "/home/aman/.ros/rtabmap.db" (0 MB).
/home/aman/catkin_ws/devel/lib/rtabmap_ros/rtabmap: symbol lookup error: /home/aman/catkin_ws/devel/lib//librtabmap_sync.so: undefined symbol: _ZN7rtabmap7Rtabmap4initERKSt3mapINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES7_St4lessIS7_ESaISt4pairIKS7_S7_EEERSB_b

what is the reason for this error? i have build the whole package again, also installed g2o but the error is not resolved.Would be really greatful if could help me.

[matlabbe]

It is like rtabmap_ros has been built with a different version of rtabmap than the libraries loaded at runtime. As you are building rtabmap_ros from source, make sure to uninstall ros-[ROS_DISTRO]-rtabmap. You can also do:

ldd /home/aman/catkin_ws/devel/lib//librtabmap_sync.so | grep rtabmap

[Aman virmani]

        librtabmap_ros.so => /home/aman/catkin_ws/devel/lib/librtabmap_ros.so (0x00007f273ac03000)
        librtabmap_core.so.0.20 => /opt/ros/melodic/lib/librtabmap_core.so.0.20 (0x00007f2737aa2000)
        librtabmap_utilite.so.0.20 => /opt/ros/melodic/lib/librtabmap_utilite.so.0.20 (0x00007f2737884000)
 this is the output shown by the command that was given above. Also I did uninstall rtabmap and also deleted the folder but still it shows the same error.

Please help have build it 3 times but same error comes

[Aman virmani]

it worked by entering this command but again stopped working.
the command was

ldd /home/aman/catkin_ws/devel/lib//librtabmap_sync.so | grep rtabmap

new to ros hope you don't mind replying to me.

[Aman virmani]

started working after reboot idk how. Btw thanks a lot.

[matlabbe]

You have rtabmap_ros built from ros linking on rtabmap installed in /opt/ros/melodic. Either make sure that rtabmap_ros version uses the same tag than the installed rtabmap, or uninstall rtabmap and build latest from source.

$ sudo apt remove ros-melodic-rtabmap