ament_copyright custom entry-point is not available while unit-testing its workspace

[alsora]

Hi, I have a workspace which includes two packages:

• my_package this is a generic ROS package. It has a custom copyright notice and it runs the ament_cmake_copyright linter as part of unit-tests.
• my_ament_copyright_extension this is a python package that provides support for my custom copyright notice and registers it as an additional entry-point for the copyright linter (similar to what this package is doing https://github.com/PickNikRobotics/picknik_ament_copyright)

When I run colcon test on this workspace, I need that the my_package unit-tests are able to see and use the custom license entry-points defined in my_ament_copyright_extension, otherwise this causes an error due to "unknown license".

Unfortunately, it looks like if I just run

colcon build
colcon test

that does not happen and the copyright linter test fails.

I noticed that in order to have it to succeed, I need to also manually call source install/setup.sh before running the test.

Although this is just a single additional command, it feels quite inconvenient, as it's not normally needed to run unit-tests.