kitty freezes under wayland

[joshuarubin]

I started mentioning this issue in #1681 but it seems to be a separate issue. kitty's been freezing up, requiring a kill -9, very frequently since version v0.14.0. I've tested using
721beb9 and it is still present.

I've had to pin my package manager to v0.13.3 as this is a very significant issue that greatly impedes my work.

I'm using sway and runnning kitty using wayland. It seems to happen when kitty loses focus (or immediately when it regains it, not sure which).

Happy to help troubleshoot. Thanks for such a great tool!

[kovidgoyal]

I'm going to need some way to reproduce it, since I cannot make it happen in sway regardless how much switching I do between kitty and other applications.

[joshuarubin]

I understand. Is there any debug log or trace I can get you that would help start narrowing it down?

[joshuarubin]

I have KITTY_ENABLE_WAYLAND=1 and here is my config (it's templated, but only for one font_size)

[kovidgoyal]

KITTY_ENABLE_WAYLAND is not used anymore. There is an option in
kitty.conf to control it and it will default to wayland under sway.
Set sync_to_monitor no in kitty.conf.

Post the output of --debug-config

and build kitty with

make debug-event-loop

and run it, it will print out event loop stages, so when it freezes we
will now what stage it froze at.

[kovidgoyal]

Also try running with XWayland (set linux_display_server to X11 in kitty.conf) does the freeze happen then also?

[joshuarubin]

$ python3 . --debug-config
kitty 0.14.2 (603533e632) created by Kovid Goyal
Linux balerion 5.1.9-arch1-1-ARCH #1 SMP PREEMPT Tue Jun 11 16:18:09 UTC 2019 x86_64
Arch Linux \r (\l)
Loaded config files: /home/jrubin/.config/kitty/kitty.conf
Running under: Wayland

Config options different from defaults:
active_border_color                Color(red=108, green=122, blue=128)
active_tab_background              Color(red=197, green=200, blue=198)
active_tab_foreground              Color(red=45, green=60, blue=70)
allow_remote_control               True
background                         Color(red=35, green=44, blue=49)
bell_border_color                  Color(red=204, green=102, blue=102)
color0                             Color(red=45, green=60, blue=70)
color1                             Color(red=165, green=66, blue=66)
color10                            Color(red=181, green=189, blue=103)
color11                            Color(red=240, green=198, blue=116)
color12                            Color(red=129, green=162, blue=190)
color13                            Color(red=178, green=148, blue=186)
color14                            Color(red=138, green=190, blue=183)
color15                            Color(red=197, green=200, blue=198)
color2                             Color(red=140, green=148, blue=64)
color3                             Color(red=222, green=147, blue=95)
color4                             Color(red=95, green=129, blue=157)
color5                             Color(red=133, green=103, blue=143)
color6                             Color(red=94, green=141, blue=135)
color7                             Color(red=108, green=122, blue=128)
color8                             Color(red=66, green=80, blue=89)
color9                             Color(red=204, green=102, blue=102)
copy_on_select                     clipboard
cursor                             Color(red=2, green=253, blue=255)
cursor_blink_interval              0.5
enabled_layouts                    ['horizontal', 'tall', 'fat', 'grid', 'vertical', 'stack']
font_family                        SFMono
font_size                          10.0
foreground                         Color(red=197, green=200, blue=198)
inactive_border_color              Color(red=66, green=80, blue=89)
inactive_tab_background            Color(red=108, green=122, blue=128)
inactive_tab_foreground            Color(red=66, green=80, blue=89)
kitty_mod                          8
macos_option_as_alt                3
macos_quit_when_last_window_closed True
scrollback_pager_history_size      16777216
selection_background               Color(red=197, green=200, blue=198)
selection_foreground               Color(red=35, green=44, blue=49)
symbol_map                         {(57344, 65535): 'SFMono Nerd Font'}
sync_to_monitor                    False
tab_bar_edge                       1
tab_separator                       │
url_color                          Color(red=2, green=253, blue=255)
Added shortcuts:
	 shift+control+h KeyAction(func='send_text', args=['all', b'\x01H'])
	 shift+control+j KeyAction(func='send_text', args=['all', b'\x01J'])
	 shift+control+k KeyAction(func='send_text', args=['all', b'\x01K'])
	 shift+control+l KeyAction(func='send_text', args=['all', b'\x01L'])
	 super+d KeyAction(func='scroll_page_down', args=())
	 super+i KeyAction(func='kitten', args=['unicode_input'])
	 super+z KeyAction(func='show_scrollback', args=())
	 super+tab KeyAction(func='next_tab', args=())
	 shift+super+comma KeyAction(func='move_tab_backward', args=())
	 shift+super+period KeyAction(func='move_tab_forward', args=())
	 shift+super+w KeyAction(func='close_window', args=())
	 shift+super+tab KeyAction(func='previous_tab', args=())
	 control+super+f KeyAction(func='toggle_fullscreen', args=())
Changed shortcuts:
	 super+minus KeyAction(func='change_font_size', args=[True, '-', 1.0])
	 super+0 KeyAction(func='change_font_size', args=[True, None, 0.0])
	 super+1 KeyAction(func='goto_tab', args=(1,))
	 super+2 KeyAction(func='goto_tab', args=(2,))
	 super+3 KeyAction(func='goto_tab', args=(3,))
	 super+4 KeyAction(func='goto_tab', args=(4,))
	 super+5 KeyAction(func='goto_tab', args=(5,))
	 super+6 KeyAction(func='goto_tab', args=(6,))
	 super+7 KeyAction(func='goto_tab', args=(7,))
	 super+8 KeyAction(func='goto_tab', args=(8,))
	 super+9 KeyAction(func='goto_tab', args=(9,))
	 super+equal KeyAction(func='change_font_size', args=[True, '+', 1.0])
	 super+s KeyAction(func='kitty_shell', args=['window'])
	 super+t KeyAction(func='new_tab_with_cwd', args=())
	 super+u KeyAction(func='scroll_page_up', args=())
	 super+w KeyAction(func='close_tab', args=())
	 super+enter KeyAction(func='new_window_with_cwd', args=())

When running after debug-event-loop (with python3 .) all I see is lots of (it seems that the event loop debugging is only useful for x11):

[26.1760] loop tick
[26.1861] loop tick
[26.1962] loop tick
[26.2062] loop tick

Until it just stops.

When running with KITTY_DISABLE_WAYLAND=1 I haven't seen it hang yet. I'll update if I do.

[joshuarubin]

I put the log output here if you want to see.

I've been able to pretty reliably reproduce it by running $ xeyes moving the cursor to the xeyes window and back to the kitty window a few times. I see a bunch of empty lines printed to the console and then it just stops.

When running under x11 mode this does not cause a hang.

[joshuarubin]

Also, it seems that setting sync_to_monitor yes fixes the issue, or perhaps just makes the issue much less frequent.

[kovidgoyal]

So it only happens with sync_to_monitor no?

[joshuarubin]

I can’t say definitively that it doesn’t happen, but I haven’t been able to reproduce it yet with sync_to_monitor yes

[kovidgoyal]

Run with it for a couple of days, and if you can confirm it, it will
help me debug.

[joshuarubin]

You got it. Thanks!

[kovidgoyal]

And just as a general note, sync_to_monitor yes is the default and recommended setting, only use no if you have some overriding reason.

[kovidgoyal]

And did it work?

[kovidgoyal]

I tried running kitty under sway as

kitty -o sync_to_monitor=n

and spent 5 mins moving the mouse back and forth between xeyes and kitty, no crashes/freezes.

Since I cannot reproduce, and I think your issue is solved by using the default sync_to_monitor setitng, am closing.