wayland fallback on X11-Ogre

[v4hn]

When running on wayland with Ogre without wayland support, explicitly force Qt to use the XCB protocol running through Xwayland.

Backported with adaptations from ros2/rviz#847 .

@rhaschke as discussed in person.
Tested on Debian trixie to run under X11 as well as wayland.

[rhaschke]

Thanks for this PR. I need to look into CI. Looks like OSRF broke Noetic by removing the urdf package key ☹️

[simonschmeisser]

What version of ogre are you using? From Debian package? Maybe wayland support can be enabled?

[v4hn]

Hi Simon, great to hear from you!

What version of ogre are you using? From Debian package?

Yes, the native packages from Debian bookworm/trixie.
Of course I could build ogre myself with adapted features, and that might work.
But I'm mostly interested in the out-of-the-box ROS-O experience, and the default build (also on the buildfarms) results in an RViz that will fail to start on any wayland installation (which is the default for a while already!).

@rhaschke

• the jammy builds seem do break due to invalid repository signatures key configs.
• for noetic, "urdf" cannot be resolved, but that's a regular package. The problem might only be that rosdep rejects eol distributions by default, but has an additional flag to include them.

Personally, I'm also fine with moving this (and any future) PR to a new ros-o branch. What do you think?

[rhaschke]

I didn't have time to look into the (general) build issues yet. Just returned from holidays...
Going for a ros-o branch seems to be the right choice if those Noetic build issues cannot be resolved.

[simonschmeisser]

Wayland support was actually only added super recently in 14.something in Ogre so this workaround will likely be needed forever