Comment # 6 on bug 1208289 from Matej Cepl

Also, support on non-bash and non-gnome-terminal seems rather limited:

Container Setup Complete!
warning: Could not set up terminal.
warning: TERM environment variable set to 'foot'.
warning: Check that this terminal type is supported on this system.
warning: Using fallback terminal type 'xterm-256color'.
fish: Unknown command: ssh-add
~/.config/fish/functions/__ssh_agent_is_started.fish (line 10): 
    ssh-add -l > /dev/null 2>&1
    ^~~~~~^
in function '__ssh_agent_is_started'
    called on line 5 of file ~/.config/fish/conf.d/60_fish-ssh-agent.fish
from sourcing file ~/.config/fish/conf.d/60_fish-ssh-agent.fish
    called on line 246 of file /usr/share/fish/config.fish
from sourcing file /usr/share/fish/config.fish
    called during startup
fish: Unknown command: fzf_key_bindings
~/.config/fish/functions/fish_user_key_bindings.fish (line 2): 
    fzf_key_bindings
    ^~~~~~~~~~~~~~~^
in function 'fish_user_key_bindings'
in function '__fish_reload_key_bindings'
    called on line 190 of file
/usr/share/fish/functions/__fish_config_interactive.fish
in function '__fish_config_interactive'
    called on line 144 of file /usr/share/fish/config.fish
in function '__fish_on_interactive'
in event handler: handler for generic event 'fish_prompt'