https://github.com/DeterminateSystems/nix-installer/blob/main/src/cli/subcommand/install.rs
    ? CommonSettings
https://github.com/DeterminateSystems/nix-installer/blob/main/src/settings.rs
    ? InitSystem (None, Launchd, Systemd)

    pub struct InitSettings {
      pub init: InitSystem,
      ...
      /// Start the daemon (if not `--init none`)
      long = "no-start-daemon"
    }
https://github.com/DeterminateSystems/nix-installer/blob/main/src/planner/linux.rs
    pub struct Linux {
        #[cfg_attr(feature = "cli", clap(flatten))]
        pub settings: CommonSettings,
        #[cfg_attr(feature = "cli", clap(flatten))]
        pub init: InitSettings,
    }
    ? start_daemon
        ...
        plan.push(
        ConfigureInitService::plan(self.init.init, self.init.start_daemon)
            .await
https://github.com/DeterminateSystems/nix-installer/blob/main/src/action/common/configure_init_service.rs 
    https://github.com/DeterminateSystems/nix-installer/blob/main/src/action/common/configure_init_service.rs#L136
        fn execute_description(&self) -> Vec<ActionDescription> {
        let mut vec = Vec::new();
        match self.init {
            #[cfg(target_os = "linux")]
            InitSystem::Systemd => {
                let mut explanation = vec![
                    "Run `systemd-tempfiles --create --prefix=/nix/var/nix`".to_string(),
                    format!("Symlink `{SERVICE_SRC}` to `{SERVICE_DEST}`"),
                    format!("Symlink `{SOCKET_SRC}` to `{SOCKET_DEST}`"),
                    "Run `systemctl daemon-reload`".to_string(),
                ];
                if self.start_daemon {
                    explanation.push(format!("Run `systemctl enable --now {SOCKET_SRC}`"));
                }
                vec.push(ActionDescription::new(self.tracing_synopsis(), explanation))
            },
    ? nix-daemon.service, nix-daemon.socket

https://github.com/DeterminateSystems/nix-installer/blob/main/src/action/mod.rs
https://github.com/DeterminateSystems/nix-installer/blob/main/src/action/common/configure_nix.rs
https://github.com/DeterminateSystems/nix-installer/blob/main/src/action/common/configure_shell_profile.rs
https://github.com/DeterminateSystems/nix-installer/blob/main/src/planner/macos.rs
    launchd
    ShellProfileLocations
https://github.com/DeterminateSystems/nix-installer/blob/main/src/planner/mod.rs#L345
    /etc/zshrc
    /etc/zsh/zshrc

    # Nix
    if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
        . '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
    fi
    # End Nix