xrandr --newmode not working (and no output)
Hey folks
I'm trying to resize a xvfb virtual display, but it seems my xrandr --newmode ...
command is not having any effect.
Here's the quick rundown:
$ Xvfb -ac :99 -screen 0 800x600x16
$ xrandr -d :99 --newmode "640x480_60.00" 23.75 640 664 720 800 480 483 487 500 -hsync +vsync # modeline generated from cvt
# No output, exit code 0 - seems to be fine
$ xrandr -d :99
Screen 0: minimum 1 x 1, current 800 x 600, maximum 800 x 600
screen connected 800x600+0+0 0mm x 0mm
800x600 0.00*
# The original screen mode is there, but my new 640x480 is not
# Obviously, --addmode fails with "cannot find mode"
This is on Ubuntu Jammy, inside a fresh Docker image (literally just docker run -it ubuntu:jammy /bin/bash
and the necessary apt-get install
setup).
Not sure if this is a problem with xrandr
or xvfb
. I've tried adding --verbose
to my xrandr --newmode
command, but still no output. Is there any way to get some additional output to help me track down where the issue might be?