ERROR: cannot launch node of type [exercise_23/publish_age.py]: can't locate node [publish_age.py] in package [exercise_23]

[steve26]

Why is this happening? How to fix it? (Exercise 2.3)

[simon.steinmann91]

Hi @steve26

make sure you source the devel/setup.bash after compiling and that the publish_age.py is made executable with chmod +x publish_age.py

[bayodesegun]

Hi @steve26,

Welcome to the Community!

As @simon.steinmann91 mentioned, it’s probably an execute permisssion issue. The full reference to this error can be found in this knowledgebase post:

ERROR: cannot launch node of type [package/file.py]: can't locate node [file.py] in package [package]

This error is very common when using ROS to launch a python node, either via rosrun or roslaunch. SOLUTION: Does the file file.py… exist in the package package? If not, create it! (Does the package itself exist and is it spelled correctly?). have execute permissions? If not, make it executable by running: chmod +x /path/to/file.py # replace '/path/to/file.py' by the real path of your file