Problem

“No module named catkin_pkg.package” on catkin_make w/ Indigo

I have the problem after anaconda is installed. I get an error because of the different PYTHONPATH used by anaconda.

Solution 1: turn off anaconda

In the end of file ~/.bashrc, you will find export PATH=”/home/YOURUSRNAME/anaconda3/bin:$PATH” .

In fact the ROS should use python in /opt/ros/indigo/lib/python2.7/dist-packages. Uncomment it and source ~/.bashrc then it works.

Solution 2:

http://answers.ros.org/question/220546/catkin_make-failure-due-to-python-anaconda/

Without turning off anaconda, just run pip install catkin_pkg, it may be helpful.

Conclusion

Basically the problem happens because ROS is confused with python location due to different path of python used by anaconda.

Here are some reference that instructs us how to navigation the specified python.

When the system cannot position python

installed python 3.5 thenI get this error: -bash: /usr/bin/python: No such file or directory

http://stackoverflow.com/questions/15236832/how-do-i-reinstall-a-directory-in-usr-bin-python

1 sudo rm /usr/bin/python # because that's a corrupted file　　
2 sudo ln -s /usr/bin/python2.7 /usr/bin/python

When you need to change the default version of python

https://linuxconfig.org/how-to-change-from-default-to-alternative-python-version-on-debian-linux

Change python version system-wide

To change python version system-wide we can use update-alternatives command. Logged in as a root user, first list all available python alternatives:

# update-alternatives --list python
update-alternatives: error: no alternatives for python

The above error message means that no python alternatives has been recognized by update-alternatives command. For this reason we need to update our alternatives table and include both python2.7 and python3.4:

# update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
update-alternatives: using /usr/bin/python2.7 to provide /usr/bin/python (python) in auto mode
# update-alternatives --install /usr/bin/python python /usr/bin/python3.4 2
update-alternatives: using /usr/bin/python3.4 to provide /usr/bin/python (python) in auto mode

When you cannot do catkin_make with the error “No module named rospkg”

http://answers.ros.org/question/39657/importerror-no-module-named-rospkg/

The reason this error occurs is because Python packages in /opt are added to PYTHONPATH environment variable BUT for ones in /usr, path does not exist in PYTHONPATH variable. The python-rospkg gets installed in /usr by default. So you just need followingline in .bashrc to fix this:

export PYTHONPATH=$PYTHONPATH:/usr/lib/python2.7/dist-packages