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Error using RQT - Could not import "pyqt" bindings of qt_gui_cpp library

asked 2020-11-27 20:13:21 -0600

liamr0y gravatar image

updated 2020-12-16 03:03:04 -0600

mgruhler gravatar image

Every time I try to use anything RQT (rqt_console, rqt_graph, etc.) I get this error (see below). Not sure how to fix this. When I do Python --version I get Python 3.7, however I ensured my environment variable $ROS_PYTHON_VERSION=2. Im on Ubuntu 18.04 using Melodic


Could not import "pyqt" bindings of qt_gui_cpp library - so C++ plugins will not be available:
Traceback (most recent call last):
  File "/opt/ros/melodic/lib/python2.7/dist-packages/qt_gui_cpp/", line 43, in <module>
    from . import libqt_gui_cpp_sip
ImportError: dynamic module does not define module export function (PyInit_libqt_gui_cpp_sip)


Note this output when I run "$ env | grep PYTHON":


How do I stop getting this error when I try to use RQT?

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I have the same issue as you have so unfortunately I don't know the answer yet. Did you meanwhile solve this error? If yes, could you please help me out? If no, I will continue to search for an answer and maybe I will be able to help you out! I couldn't find a lot of other topics related to this error.



alme96 gravatar image alme96  ( 2020-12-15 09:40:58 -0600 )edit

The first step would be to make sure /usr/bin/python is a symbolic link to `python2.7'.

$ ls -l /usr/bin/python
lrwxrwxrwx 1 root root       9 Apr 16  2018 /usr/bin/python -> python2.7
Mike Scheutzow gravatar image Mike Scheutzow  ( 2022-06-03 14:11:26 -0600 )edit

1 Answer

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answered 2022-06-03 12:39:35 -0600

I had the same problem, and solved it as follows:

gives a priority of 1 for the path of python3

[sudo] update-alternatives --install /usr/bin/python python /usr/bin/python3 1

gives a priority of 2 for the path of python2 (highest priority)

[sudo] update-alternatives --install /usr/bin/python python /usr/bin/python2 2
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Asked: 2020-11-27 20:13:21 -0600

Seen: 444 times

Last updated: Jun 03 '22