Launch file for lifecycle_demo_launch.py should be converted to new-style launch

[ros2]

Launch file for lifecycle_demo_launch.py should be converted to new-style launch

[clalancette]

I'll update the title.

[dhood]

That file uses "legacy" launch and hasn't been converted for use with ros2 launch yet. Did you find reference to that invocation in a tutorial, or were you just inspired because of the name (which would be reasonable also)?

[wjwwood]

(also the recommended syntax for ros2 launch is ros2 launch <package name> <launch_file.launch.py>)

[clalancette]

That file uses "legacy" launch and hasn't been converted for use with ros2 launch yet. Did you find reference to that invocation in a tutorial, or were you just inspired because of the name (which would be reasonable also)?

Just inspired by the name; I went looking for things that I could launch, and happened on this one :). This isn't a priority to fix for bouncy, I just thought I would open the bug while I was here testing.

[dhood]

Yes, I doubt you would be the only person to be misled

[Karsten1987]

I can second that. Invoking the launch file with the classical launch command works well for me.

[wjwwood]

If you leave this open, then I'd say you should change the title, because the launch file can be used (with the old launch command), instead there should be an issue about converting this launch file to the new launch format or something like that.

[wjwwood]

I added a better error message for this case in ros2/launch#93

[mikaelarguedas]

fixed in #262

@ironmig Tip: you can use the github keywords "fixes" or "closes" if you want issue to be closed automatically when merging.