Hi,

I'm using mpv a lot and on the latest guix pull it stopped working with
this error message:

klm@pal ~ ➤ mpv
https://download.blender.org/durian/trailer/sintel_trailer-480p.ogv
[ffmpeg/demuxer] ogg: Broken file, keyframe not correctly marked.
 (+) Video --vid=1 'Sintel Trailer' (theora 854x480)
 (+) Audio --aid=1 (vorbis 2ch 48000Hz)
[vo/gpu] VT_GETMODE failed: Inappropriate ioctl for device
[vo/gpu/opengl] Failed to set up VT switcher. Terminal switching will be
unavailable.
[vo/gpu] Failed to commit ModeSetting atomic request (-13)
[vo/gpu/opengl] Failed to set CRTC for connector 95: Permission denied
Error opening/initializing the selected video_out (--vo) device.
Video: no video

Exiting... (Errors when loading file)
klm@pal ~ ➤ readlink $(which mpv)
/gnu/store/3i6dmnksdr4sif66hlgh1g0dxfqwxzsi-mpv-0.35.0/bin/mpv

After some looking around a bit, I found that gpu-contexts have changed:

klm@pal ~ ➤ mpv -gpu-context help
GPU contexts (APIs):
    auto (autodetect)
    wayland (opengl)
    drm (opengl)
klm@pal ~ ➤ /gnu/store/2chvq95z20s7xihyayiayiy40fvyqn0g-mpv-0.34.1/bin/mpv
-gpu-context help
GPU contexts (APIs):
    auto (autodetect)
    wayland (opengl)
    x11egl (opengl)
    drm (opengl)

I don't know if it's relevant but may help tracking the cause of this
problem down. mpv 0.34.0 works without problems.
I found this recent patch on mpv: https://issues.guix.gnu.org/28457

Is it possible that mpv's default configuration has changed and is now
causing problems for old X11 setups?
I'm in integrated Intel graphics, Linux-Libre 6.0.8-gnu #1 SMP
PREEMPT_DYNAMIC 1 x86_64 GNU/Linux

Thanks,
K.