Unable to start sway

[J0nnyMak0]

sway version 1.2-d510684c (Jan 2 2020, branch 'master')

I'm trying to run sway on my 2-in-1 with the following gpu info:

00:02.0 VGA compatible controller: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07) (prog-if 00 [VGA controller])
00:13.0 Non-VGA unclassified device: Intel Corporation Sunrise Point-LP Integrated Sensor Hub (rev 21)

and sway fails to startup with the error:

2020-01-02 15:38:06 - [sway/main.c:152] Linux alpha12 5.4.7-arch1-1 #1 SMP PREEMPT Tue, 31 Dec 2019 17:20:16 +0000 x86_64 GNU/Linux
2020-01-02 15:38:06 - [sway/main.c:168] Contents of /etc/os-release:
2020-01-02 15:38:06 - [sway/main.c:152] NAME="Arch Linux"
2020-01-02 15:38:06 - [sway/main.c:152] PRETTY_NAME="Arch Linux"
2020-01-02 15:38:06 - [sway/main.c:152] ID=arch
2020-01-02 15:38:06 - [sway/main.c:152] BUILD_ID=rolling
2020-01-02 15:38:06 - [sway/main.c:152] ANSI_COLOR="0;36"
2020-01-02 15:38:06 - [sway/main.c:152] HOME_URL="https://www.archlinux.org/"
2020-01-02 15:38:06 - [sway/main.c:152] DOCUMENTATION_URL="https://wiki.archlinux.org/"
2020-01-02 15:38:06 - [sway/main.c:152] SUPPORT_URL="https://bbs.archlinux.org/"
2020-01-02 15:38:06 - [sway/main.c:152] BUG_REPORT_URL="https://bugs.archlinux.org/"
2020-01-02 15:38:06 - [sway/main.c:152] LOGO=archlinux
2020-01-02 15:38:06 - [sway/main.c:140] LD_LIBRARY_PATH=/usr/local/lib:
2020-01-02 15:38:06 - [sway/main.c:140] LD_PRELOAD=(null)
2020-01-02 15:38:06 - [sway/main.c:140] PATH=/opt:/home/am/.scripts:/home/am/usr/local/bin:/home/am/.gem/ruby/2.3.0/bin:/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
2020-01-02 15:38:06 - [sway/main.c:140] SWAYSOCK=(null)
2020-01-02 15:38:06 - [sway/server.c:40] Preparing Wayland server initialization
2020-01-02 15:38:06 - [backend/session/logind.c:821] Successfully loaded logind session
2020-01-02 15:38:06 - [backend/session/logind.c:75] Failed to take device '/dev/dri/card0': Operation not permitted
2020-01-02 15:38:06 - [backend/backend.c:192] Found 0 GPUs
2020-01-02 15:38:06 - [backend/backend.c:343] Failed to open any DRM device
2020-01-02 15:38:06 - [backend/noop/backend.c:51] Creating noop backend
2020-01-02 15:38:06 - [sway/server.c:47] Unable to create backend

[ddevault]

Are you using an Arch system without systemd?

[J0nnyMak0]

Sorry for the noise. My installation was borked. Fixed it and everything working now!

[J0nnyMak0]

I'm going to reopen this. It seems to happen randomly. A reboot seems to fix it sometimes...

[J0nnyMak0]

Are you using an Arch system without systemd?

I'm using systemd

[jameswalmsley]

See #4672

[phragment]

It seems to happen randomly. A reboot seems to fix it sometimes...

I experienced the same error today. Early KMS or adding the user to video group etc did not help.
In my opinion this is probably a race condition when using lightdm, between the Xorg displaying the greeter shutting down and the subsequent startup of sway.
In my case adding a sleep 1 in the Arch Linux session-wrapper (/etc/lightdm/Xsession) before the exec fixes this reliably for me.

HTH

edit: Maybe this should be a follow-up to #4672

[bl4ckb0ne]

Closing, as display managers are not officially supported. Feel free to improve the wiki if you want to share your solution.

[schauveau]

@phragment Indeed! I had a similar problem a long time ago.
I think that lightdm starts executing /etc/X11/Xsession before the VT switch is done.
So a typical race condition. The symptoms can be missing input devices, a black screen followed by a timeout error from wlroots.

canonical/lightdm#63

I wonder how many users are trying sway and give up immediately because of that stupid behavior. But you know, «display managers are not officially supported».