Installation fails when system modes src is a symbolic link

[norro]

Minor, low-priority issue but curious:
The system modes package build/installation seems to fail, if the package sources are not placed in the ros2 workspace, but just (symbollically) linked into the workspace

[norro]

Could not reproduce, @nielsvd.
Tried on Ubuntu 20.04, symbolic link in ROS2 2 workspace pointing to system modes sources outside the workspace. Symbolic link was not spanning any directories without read access, though.

[norro]

Do you want to look into this further, @nielsvd?