라라벨 Error in plugin 'gulp-notify'

문제상황

root@zetawiki:/var/www/laravel# gulp
[00:26:55] Using gulpfile /var/www/laravel/gulpfile.js
[00:26:55] Starting 'default'...
[00:26:55] Starting 'sass'...

Fetching Sass Source Files...
   - resources/assets/sass/zeta.scss


Saving To...
   - ../public/css/zeta.css

[00:26:56] Finished 'default' after 1.31 s
[00:26:57] gulp-notify: [Laravel Elixir] Sass Compiled!
[00:26:57] gulp-notify: [Error in notifier] Error in plugin 'gulp-notify'
Message:
    not found: notify-send
Details:
    code: ENOENT
[00:26:57] Finished 'sass' after 1.71 s
root@zetawiki:/var/www/laravel#