Troubleshooting

What You Should Try First

Make sure your workspace is built

$ build_ros

and make sure your workspace is sourced after you added new packages/nodes!

$ source ~/.zshrc

I cannot run my node!

Problem

You get a python exceptions with the last line of

Traceback (most recent call last):
...

being the following error

OSError: [Errno 8] Exec format error: <path/to/your/node>

Solution

You have forgotten to add

#!/usr/bin/env python3

as first line of your node. Better add it now.

Problem

You get the output

No executable found

Solution

Double check that the node exists, gets installed (CMakeLists.txt, see Run A Node), and is executable. If you have forgotten to make it executable (most likely reason of the before mentioned causes), run

$ chmod +x <PATH_TO_YOUR_NODE>

I cannot start the simulation!

Problem

You are using Ubuntu in a Virtual Machine and Gazebo dies after a few seconds and you get the following Output:

[gz-4] terminate called after throwing an instance of ‘Ogre::RenderingAPIException’
[gz-4]   what():  OGRE EXCEPTION(3:RenderingAPIException): Fragment Program 100000002PixelShader_ps failed to compile. See compile log above for details. in GLSLShader::compile at ./.obj-aarch64-linux-gnu/gz_ogre_next_vendor-prefix/src/gz_ogre_next_vendor/RenderSystems/GL3Plus/src/GLSL/OgreGLSLShader.cpp (line 361)

The VM is trying to render with hardware to which is does not have full access.

Solution

Run the following command:

$ echo ‘export LIBGL_ALWAYS_SOFTWARE=1’ >> ~/.zshrc \
&& . ~/.zshrc