roslaunch Error

[darkasassin44]

I have checked reqiurements.txt successfully, and only remained launch the demo.launch file.

conceptbug95@ubuntu:~$ roslaunch mqtt_bridge demo.launch
... logging to /home/conceptbug95/.ros/log/f08b33d8-eb5e-11ea-bbdb-001c42b01667/roslaunch-ubuntu-32640.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://localhost:36857/

SUMMARY
========

PARAMETERS
 * /mqtt_bridge/bridge: [{'topic_from': '...
 * /mqtt_bridge/deserializer: msgpack:loads
 * /mqtt_bridge/mqtt/client/protocol: 4
 * /mqtt_bridge/mqtt/connection/host: 10.0.0.254
 * /mqtt_bridge/mqtt/connection/keepalive: 60
 * /mqtt_bridge/mqtt/connection/port: 1883
 * /mqtt_bridge/serializer: msgpack:dumps
 * /rosdistro: melodic
 * /rosversion: 1.14.9

NODES
  /
    mqtt_bridge (mqtt_bridge/mqtt_bridge_node.py)

ROS_MASTER_URI=http://localhost:11311

running rosparam delete /mqtt_bridge/
process[mqtt_bridge-1]: started with pid [32660]
Traceback (most recent call last):
  File "/home/conceptbug95/catkin_ws/src/mqtt_bridge/scripts/mqtt_bridge_node.py", line 5, in <module>
    from mqtt_bridge.app import mqtt_bridge_node
  File "/home/conceptbug95/catkin_ws/src/mqtt_bridge/src/mqtt_bridge/app.py", line 8, in <module>
    from .bridge import create_bridge
  File "/home/conceptbug95/catkin_ws/src/mqtt_bridge/src/mqtt_bridge/bridge.py", line 10, in <module>
    from .util import lookup_object, extract_values, populate_instance
  File "/home/conceptbug95/catkin_ws/src/mqtt_bridge/src/mqtt_bridge/util.py", line 5, in <module>
    from rosbridge_library.internal import message_conversion
  File "/home/conceptbug95/catkin_ws/src/rosbridge_suite/rosbridge_library/src/rosbridge_library/internal/message_conversion.py", line 45, in <module>
    from rosbridge_library.util import string_types, bson
  File "/home/conceptbug95/catkin_ws/src/rosbridge_suite/rosbridge_library/src/rosbridge_library/util/__init__.py", line 24, in <module>
    "BSON installation does not support all necessary features. "
Exception: BSON installation does not support all necessary features. Please use the MongoDB BSON implementation. See: https://github.com/RobotWebTools/rosbridge_suite/issues/198
[mqtt_bridge-1] process has died [pid 32660, exit code 1, cmd /home/conceptbug95/catkin_ws/src/mqtt_bridge/scripts/mqtt_bridge_node.py __name:=mqtt_bridge __log:=/home/conceptbug95/.ros/log/f08b33d8-eb5e-11ea-bbdb-001c42b01667/mqtt_bridge-1.log].
log file: /home/conceptbug95/.ros/log/f08b33d8-eb5e-11ea-bbdb-001c42b01667/mqtt_bridge-1*.log
all processes on machine have died, roslaunch will exit
shutting down processing monitor...
... shutting down processing monitor complete
done

But I don't know how to fix this error.
Even there are no error codes or error messages.

PLEASE guide me how to solve this problem if you know how to do.

[asoriano1]

do this:

sudo pip uninstall bson
python -m pip install pymongo

[darkasassin44]

I'm a beginner with Ubuntu, so is there any difference between
python -m pip install pymongo and pip install pymongo?
I solved this problem yesterday just before I left my office, but cannot understand your suggestion.
Of course, your suggestion also works too! :)

[joko06]

@darkasassin44 How did you solved this problem?