Segfault when config: `visual_bell_duration 1 linear(0, 1)`

[jkoop]

Describe the bug

Kitty crashed (segmentation fault) when I set visual_bell_duration to 1 linear(0, 1)

To Reproduce
Steps to reproduce the behavior:

1. Set visual_bell_duration to 1 linear(0, 1)
2. Reload config
3. Cause a terminal bell echo -e '\a'
4. Crashes

Screenshots
n/a

Environment details

kitty 0.42.1 (d56721e64d) created by Kovid Goyal
Linux joes-framebook 6.8.0-60-generic #63-Ubuntu SMP PREEMPT_DYNAMIC Tue Apr 15 19:04:15 UTC 2025 x86_64
Linux Mint 22 Wilma joes-framebook /dev/tty

DISTRIB_ID=LinuxMint
DISTRIB_RELEASE=22
DISTRIB_CODENAME=wilma
DISTRIB_DESCRIPTION="Linux Mint 22 Wilma"
Running under: Wayland (GNOME Shell 46.0) missing: blur server_side_decorations cursor_shape layer_shell icon bell window-tag
OpenGL: '4.6 (Core Profile) Mesa 24.2.8-1ubuntu1~24.04.1' Detected version: 4.6
Frozen: True
Fonts:
  medium: DejaVuSansMono: /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf:0
          Features: ()
    bold: DejaVuSansMono-Bold: /usr/share/fonts/truetype/dejavu/DejaVuSansMono-Bold.ttf:0
          Features: ()
  italic: DejaVuSansMono-Oblique: /usr/share/fonts/truetype/dejavu/DejaVuSansMono-Oblique.ttf:0
          Features: ()
      bi: DejaVuSansMono-BoldOblique: /usr/share/fonts/truetype/dejavu/DejaVuSansMono-BoldOblique.ttf:0
          Features: ()
Paths:
  kitty: /home/joek/.local/kitty.app/bin/kitty
  base dir: /home/joek/.local/kitty.app/lib/kitty
  extensions dir: /home/joek/.local/kitty.app/lib/kitty-extensions
  system shell: /bin/bash
System color scheme: dark. Applied color theme type: none
Loaded config files:
  /home/joek/.config/kitty/kitty.conf

Config options different from defaults:
bell_on_tab          🟢
bell_path            /home/joek/Documents/terminal-bell.oga
cursor_shape         3
visual_bell_duration (1.0, kitty.options.utils.EasingFunction(type='linear', linear_x=(0.0, 1.0), linear_y=(0, 1.0)), kitty.options.utils.EasingFunction())
Colors:
	visual_bell_color    #33ff11   

Important environment variables seen by the kitty process:
	PATH                                /home/joek/.local/kitty.app/bin:/home/joek/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
	LANG                                en_CA.UTF-8
	SHELL                               /bin/bash
	DISPLAY                             :0
	WAYLAND_DISPLAY                     wayland-0
	USER                                joek
	XDG_DATA_DIRS                       /usr/share/ubuntu:/usr/share/gnome:/home/joek/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share/:/usr/share/
	XDG_RUNTIME_DIR                     /run/user/1000
	XDG_CONFIG_DIRS                     /etc/xdg/xdg-ubuntu:/etc/xdg
	XDG_CURRENT_DESKTOP                 ubuntu:GNOME
	XDG_MENU_PREFIX                     gnome-
	XDG_SESSION_CLASS                   user
	XDG_SESSION_DESKTOP                 ubuntu
	XDG_SESSION_TYPE                    wayland

Additional context

Minimal config:

visual_bell_duration 1 linear(0, 1)