This is ~/.ssh/rc
#!/bin/sh
if [ -n "$SSH_AUTH_SOCK" -a -n "$XDG_RUNTIME_DIR" ]; then
ln -sf "$SSH_AUTH_SOCK" "$XDG_RUNTIME_DIR/.ssh-agent.socket"
fi
This is ~/.config/fish/conf.d/ssh.fish
if status is-interactive
if set -q SSH_AUTH_SOCK and set -q XDG_RUNTIME_DIR
if test -e "$XDG_RUNTIME_DIR/.ssh-agent.socket"
set -gx SSH_AUTH_SOCK "$XDG_RUNTIME_DIR/.ssh-agent.socket"
end
end
end