Which operating system does the issue occur on?
OS X 10.12.6 (16G29)

My alacritty.yml configuration contains such strange thing:

key_bindings:
  - { key: LBracket, mods: Command|Shift, command: { program: "/usr/local/bin/tmux", args: ["prev"] } }
  - { key: RBracket, mods: Command|Shift, command: { program: "/usr/local/bin/tmux", args: ["next"] } }

Each time I trigger command execution with Cmd+Shift+[ or ] I'm getting more and more zombie processes of tmux in my system. Unfortunately I have very small ulimit on processes (1000 hard) and after some time I'm hitting fork error in all shell windows. Re-launching alacritty works (all processes are collected by system on alacritty exit). Seems that alacritty doesn't wait for spawned processes.

If you need any additional information or debug logs, feel free to ping me here.

Thanks.