I have a super weird bug which I can not explain. Neither can I directly blame nixpkgs, so I am not opening an issue but posting this here. Maybe other people have the same problem, so we can suffer together?
At work, I have a Lenovo P14s Gen 4 (21K6) laptop (AMD with amdgpu driver). I also have a very nice ThinkPad Universal USB-C dock. The dock is connected to two Philips 278B Monitors, via Displayport. All of this might or might not be relevant.
On Monday, 2024-07-15 everything was working fine. I usually work on my two large screens with the laptop lid closed. Then I was ill for a couple of days. On Friday, 2024-07-19 I went to work, but still did not feel that healthy, so to protect my coworkers I took my laptop home. There, I have the same dock, but only one screen. This Monday, 2024-07-29 I went on a conference and came back today, 2024-07-25.
I connected my laptop to the dock, and only the left screen lit up. The other said “no video input”. Very seldom, I have already had similar problems, especially with my dock and laptop at home. Power cycling the dock usually fixes that. It did not help. I unplugged the Displayport cable and reconnected it. Ta-da! The right screen turned on and the left screen turned off.
I can repeat this forever, switching between my two screens, but they never work at the same time. On the contrary, GNOME thinks that both were working.
I am using GNOME on Wayland. Switching by reboot, I discovered that NixOS 24.05.20240707.1948467 works fine. I will bisect a little more and return here to report.
