I had a problem with initializing a ROS node in python in a larger project. The following minimum reproducible example has the same issue:

#!/usr/bin/env python

import rospy

if __name__ == '__main__':
    print("Init node")
    rospy.init_node('testNode', anonymous=True)
    print("Node initialized")

Only the "Init node" is printed, and the script freezes in the rospy.init_node() call.

roscore is already running, confirmed by rostopic list returning the /rosout topic.

I have tried reinstalling ros and all python packages, as well as rebuilding the ros project.

When debugging using pdb, the program is stuck in the following loop:

while hasattr(f, "f_code"):

    co = f.f_code
    filename = os.path.normcase(co.co_filename)
    if filename == file_name and f.f_lineno == lineno and co.co_name == func_name:
    if f.f_back:
    f = f.f_back

in the following path: */opt/ros/noetic/lib/python3/dist-packages/rosgraph/roslogging.py(64)findCaller() *

Any help would be greatly appreciated!


It is also not possible to ctrl + c to stop the process, and I have to close the terminal for it to stop.

If I comment out the call to logger.info("init_node, name[%s], pid[%s]", resolved_node_name, os.getpid()) which leads to the infinite loop as shown above, the program instead gets stuck in the following loop:

while not node.uri and not is_shutdown():
    time.sleep(0.00001) #poll for XMLRPC init

in /opt/ros/noetic/lib/python3/dist-packages/rospy/impl/init.py(105)start_node()

  • 1
    $\begingroup$ This is a highly used part of the system by a lot of users. Based on where you're having issues are you on a non-standard system? What method have you used to install your system? What is your larger system? And what else has your larger system changed about your deployment from a standard system. There has to be something different on your system than the systems on which this has been running for the last 5 years or so since this code was last changed. Please edit your question to add this additional information. $\endgroup$
    – Tully
    Commented Feb 12 at 22:05

1 Answer 1


Fixed by running

sudo apt-get remove ros-* 

then reinstalling using http://wiki.ros.org/noetic/Installation/Ubuntu, and creating a new conda environment. Not sure what actually caused the issue.


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