setting target-ros2-distro pulls source packages from a newer distro by default

[rotu]

Description

Using target-ros2-distro is unintuitive, clobbering packages with a newer source version.

Expected Behavior

I expect setting the target distribution to update the repo filetarget-ros2-distro: foxy to make vcs-repo-file-url default to https://raw.githubusercontent.com/ros2/ros2/foxy/ros2.repos

Actual Behavior

No matter the target-ros2-distro, the repos file defaults to: vcs-repo-file-url: https://raw.githubusercontent.com/ros2/ros2/master/ros2.repos

To Reproduce

https://github.com/rotu/colcon-cmake/runs/1022669117

System (please complete the following information)

https://github.com/rotu/colcon-cmake/runs/1022669117

[christophebedard]

Using target-ros2-distro is unintuitive, clobbering packages with a newer source version.

I agree with this.

Having to set vcs-repo-file-url to "" for a pretty standard use-case (avoiding building a distro from source) feels weird.

I think having two separate mandatory options would be better:

• binary install or from source
  • E.g. "binary" or "source", any other value is invalid (unless there's a better way to do this).
  • If binary install, assume that setup-ros was used to do the install. Source the right setup file using the distro name from the other option.
  • If from source, import https://raw.githubusercontent.com/ros2/ros2/$DISTRO/ros2.repos (using the distro name from the other option). Make sure to use master instead of rolling.
• distro name

And the vcs-repo-file-url option can actually be used for additional repos files, with a default value of "" aka no additional repos files.

[emersonknapp]

I would agree with defaulting vcs-repo-file-url: "" as an initial easy step - we probably shouldn't be pulling in extraneous sources at all unless specified, for CI