Using Grunt uglify task to mangle JS code

I'm attempting to use the Grunt uglify task to mangle my javascript code, and while I can make minify work, I can't figure out how to pass the 'mangle' option. My Gruntfile contains:

uglify: {
  dist: {
    mangle: true,
    files: {
      '<%= yeoman.dist %>/scripts/scripts.js': [
        '<%= yeoman.dist %>/scripts/scripts.js'
      ]
    }
  }
},

...

  grunt.registerTask('build', [
    'clean:dist',
    'wiredep',
    'useminPrepare',
    'concurrent:dist',
    'autoprefixer',
    'concat',
    'ngAnnotate',
    'uglify',
    'copy:dist',
    'cdnify',
    'cssmin',
    'filerev',
    'usemin',
  ]);

With this setup, when I run "grunt build" the uglify task reports success, and my javascript is minified, but not mangled. Can anyone tell me what I'm doing wrong?

You need to put mangles in an options object, either at task or target level, for example:

uglify: {
  dist: {
    options: {
        mangle: true,
    },
    files: {
      '<%= yeoman.dist %>/scripts/scripts.js': [
        '<%= yeoman.dist %>/scripts/scripts.js'
      ]
    }
  }
},