some bug with merge stream about gulp-modernizr HOT 2 CLOSED

gulp.task('compile:js:custom:modernizr', function (done) {
    var async = require('async');
    var directories = getDirectories({
        src: [
            '<%= paths.build[part].css %>/**/*.css',
            '<%= paths.build[part].js %>/**/*.js',
            '!**/modernizr*.js'
        ],
        dest: '<%= paths.build[part].componentsJs %>/modernizr'
    });

    async.mapSeries(directories, function (directory, callback) {
        gulp.src(directory.src)
            // Todo: add classPrefix and remove hidden test later
            .pipe(plugins.modernizr(
                {
                    options: [
                        'setClasses',
                        'testProp',
                        'fnBind'
                    ],
                    excludeTests: ['hidden']
                }
            ))
            .pipe(environment >= 2 ? plugins.uglify() : gutil.noop())
            .pipe(environment >= 2 ? plugins.rename({
                suffix: '.min'
            }) : gutil.noop())
            .pipe(gulp.dest(directory.dest))
            .on('end', function () {
                console.log('end');
                callback();
            });
    }, function (error) {
        if (error) {
            console.log(error);
        }
        done();
    });
});