"Fatal error: spawn EACCES" Running "sass:dist" task

Question

I'm creating a small Flask app and am using Gruntjs for watch, concat, and sass tasks. When I run the "Grunt" command, it throws an error: "Fatal error: spawn EACCES" and stops watching.

I've tried adding a single livereload option to the watch task as suggested in a previous question: Grunt Watch Fatal error: listen EACCES and livereload, but that did not resolve the problem.

What might be causing this error?

Grunt log:

Running "flaskServer" task
Starting the Flask server on port 5000

Running "concat:dist" (concat) task
File "./static/js/app.js" created.

Running "sass:dist" (sass) task
Fatal error: spawn EACCES

Gruntfile.js:

module.exports = function(grunt) {
  require('load-grunt-tasks')(grunt);
  grunt.initConfig({
    concat: {
      options: {
        separator: "\n",
      },
      dist: {
        src: ['assets/**/*.js'],
        dest: './static/js/app.js'
      },
    },
    sass: {
      dist: {
        options: {
          style: 'expanded'
        },
        files: [{
          expand: true,
          cwd: 'assets',
          src: ['*.scss','!_*.scss'],
          dest: './static/css',
          ext: '.css'
        }]
      }
    },
    watch: {
      javascripts: {
        options: {
          livereload: true
        },
        files: ['assets/js/*.js'],
        tasks: ['concat']
      },
      styles: {
        options: {
          livereload: true
        },
        files: ['assets/**.scss'],
        tasks: ['sass']
      },
      templates: {
        options: {
          livereload: true
        },
        files: ['templates/**/*.html'],
        tasks: [] // empty for livereload
      }
    }
  });

  grunt.registerTask('flaskServer', 'runs the flask server', function() {
    grunt.log.writeln('Starting the Flask server on port 5000');
    var spawn = require('child_process').spawn;
    var server = spawn('./run.sh');
    server.stdout.on('data', function(data) {
      grunt.log.writeln('FLASK LOG: ' + data);
    });
    process.on('exit', function() {
      server.kill();
    });
  });

  grunt.registerTask('dev', [
    'concat',
    'sass',
    'watch'
  ]);

  grunt.registerTask('server', [
    'flaskServer'
  ]);

  grunt.registerTask('default', [
    'server',
    'dev'
  ]);
};

File structure:

/assets
  /js
    app.js
  _normalize.scss
  app.scss
/node_modules
  /grunt
  /grunt-contrib-concat
  /grunt-contrib-copy
  /grunt-contrib-sass
  /grunt-congrib-watch
  /load-grunt-tasks
/static
  /css
    app.css
  /js
    app.js
/templates
  /layouts
    base.html
  /pages
  404.html
  index.html
app.py
Gruntfile.js
package.json
run.sh

Answer 1

I was able to resolve this by enabling user executable permissions on the run.sh file.

chmod u=rwx run.sh

Answer 2

Execute grunt command with sudo i.e sudo grunt.