Problem with sway in nixos-rebuild build-vm - How to configure vm?

olaf · July 10, 2022, 6:58pm

I am building a vm using rebuild-nixos build-vm with my current configuration.
When I try to log into sway it fails and produces the following log entries:

Jul 11 02:31:49 nixos gdm-password][2384]: gkr-pam: gnome-keyring-daemon started properly and unlocked keyring
Jul 11 02:31:50 nixos /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[2395]: 00:00:00.070 [ERROR] [wlr] [backend/drm/drm.c:52] PRIME import not supported
Jul 11 02:31:50 nixos /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[2395]: 00:00:00.074 [ERROR] [wlr] [backend/backend.c:228] Failed to create DRM backend
Jul 11 02:31:50 nixos /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[2395]: 00:00:00.074 [ERROR] [wlr] [backend/backend.c:239] Could not successfully create backend on any GPU
Jul 11 02:31:50 nixos /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[2395]: 00:00:00.075 [ERROR] [wlr] [backend/backend.c:386] Failed to open any DRM device
Jul 11 02:31:50 nixos /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[2395]: 00:00:00.087 [ERROR] [sway/server.c:56] Unable to create backend

It seems to be a sway issue with VMs/qemu (https://www.reddit.com/r/swaywm/comments/plcq6r/swaywm_doesnt_work_when_opened_inside_of/)
in this thread is also mentioned how it is solved for nixpkgs tests: https://github.com/NixOS/nixpkgs/blob/653038c38dee95539f74480e955a2c95000be732/nixos/tests/sway.nix#L49

My question is: How to configure qemu when setup/configured/used with the command
rebuild-nixos build-vm?

olaf · July 10, 2022, 7:43pm

I found this issue: https://github.com/NixOS/nixpkgs/issues/59219
with the answer/workaround to use QEMU_OPTS environment varibables. so i run
QEMU_OPTS="-vga none -device virtio-gpu-pci" QEMU_NET_OPTS="hostfwd=tcp::2222-:22" ./result/bin/run-nixos-vm
Unfortunately it doesn’t solve the issue that sway doesn’t run in qemu it gives the following log messages:

Jul 11 03:34:44 keintop gdm-password][1724]: gkr-pam: gnome-keyring-daemon started properly and unlocked keyring
Jul 11 03:34:44 keintop kernel: rfkill: input handler enabled
Jul 11 03:34:44 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: libEGL warning: DRI2: failed to create dri screen
Jul 11 03:34:44 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.112 [ERROR] [wlr] [EGL] command: eglInitialize, error: EGL_NOT_INITIALIZED (0x3001), message: "DRI2: failed to create screen"
Jul 11 03:34:44 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: libEGL warning: NEEDS EXTENSION: falling back to kms_swrast
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.945 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.945 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.945 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.946 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.947 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.948 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.949 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.950 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.951 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.951 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.951 [ERROR] [wlr] [render/allocator/gbm.c:114] gbm_bo_create failed
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.951 [ERROR] [wlr] [render/swapchain.c:109] Failed to allocate buffer
Jul 11 03:34:45 keintop /nix/store/5h70fw6kdfhbipqwqxdxcb2kg6gqdsc4-gdm-42.0/libexec/gdm-wayland-session[1742]: 00:00:00.951 [ERROR] [sway/config/output.c:501] Failed to commit output Virtual-1
Jul 11 03:34:55 keintop polkitd[771]: Unregistered Authentication Agent for unix-session:c2 (system bus name :1.59, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)

olaf · July 10, 2022, 8:33pm

There where two problems on the one hand that the qemu options changed so one needs a different device driver and a specification of the display. This can be set via cli environment variables (see above) or in the configuration file as described below:

  imports = [ <nixpkgs/nixos/modules/virtualisation/qemu-vm.nix>  ];
  virtualisation.qemu.options = ["-vga none" "-device virtio-vga-gl" "-display gtk,gl=on"];