anchor.diff:      environment.systemPackages =
         [ # Include bash package
           pkgs.bashInteractive
  +      ] ++ optional cfg.enableCompletion pkgs.bash-completion;
  +
  +    environment.pathsToLink =
  +      [ "/etc/bash_completion.d"
  +        "/share/bash-completion/completions"
         ];
   
       environment.loginShell = mkDefault "${shell}/bin/bash -l";
  
positive.code:       ${config.environment.interactiveShellInit}
        ${cfg.interactiveShellInit}
  
        # Read system-wide modifications.
        if test -f /etc/bash.local; then
          . /etc/bash.local
        fi
      '';
  
  
negative.code:     programs.bash.enable = mkOption {
        type = types.bool;
        default = false;
        description = "Whether to configure bash as an interactive shell.";
      };
  
      programs.bash.interactiveShellInit = mkOption {
        default = "";
        description = "Shell script code called during interactive bash shell initialisation.";
        type = types.lines;
      };
  
      programs.bash.enableCompletion = mkOption {
        type = types.bool;
        default = true;
        description = "Enable bash completion for all interactive bash shells.";
      };
  
    };
  