Darxus, a Wayland enthusiast and Phoronix Forums moderator, shared on the mailing list what killed his motivation to play with Wayland. He was once very involved with the upstream Wayland community, but that's not so much the case anymore. Here's a synopsis of his reasons:
- A particular Mesa bug destroyed his build testing setup and hasn't been fixed even though he pointed out the faulty Mesa commit dating back three months.
- There's an XWayland segmentation fault bug. Though there was an old patch to fix the segfault for XWayland, it wasn't updated and merged.
- Cairo's current build testing is a mess. Cairo does have a big build test suite, but it seems no one has ever gotten all the tests to pass in recent times. There was a patch improving the situation, but three months have passed without it being merged.
Is anything holding you back from playing with Wayland now that KDE Plasma can run on Wayland? If you're still unsure about this X11 and Mir alternative, read the very interesting Wayland Facts article.