On Tue, 2021-06-22 at 12:19 -0700, Adam Williamson wrote:
I'm seeing it too (Kevin and I talked about it last night, but couldn't work out the problem). My upgrade package set was:
garnacho suggested setting MESA_LOADER_DRIVER_OVERRIDE=i965 in /etc/environment, and that does indeed seem to work around the problem. I have Wayland again now. Though it makes it even weirder that downgrading mesa doesn't solve the problem, but it definitely doesn't, I've tried twice. And I tried older mesa+older kernel as well, no dice.
OK, so digging into this a bit further, I noticed glibc actually got updated a long way in my last upgrade. It went from glibc-2.33.9000- 2.fc35.x86_64 to glibc-2.33.9000-23.fc35.x86_64 . It seems a lot of the intermediate builds were done in side tags and not tagged, and rawhide only went from -2 to -18 in 20210617.n.0; the last time I updated my system before yesterday was on the 16th.
Kevin checked and saw he also had -2 until he updated, and when he tried downgrading, he didn't go back that far. So, I suspect glibc is the culprit here. I did try downgrading all the way back to -2 to verify, but it more or less bricked my system; I could try again but I think I'd have to downgrade virtually everything that got upgraded in the transaction to avoid bricking, which wouldn't prove much.
I'm just gonna go ahead and file a glibc bug and we'll see if we can figure it out there. For now I'm using current packages with the MESA_LOADER_DRIVER_OVERRIDE workaround.