Assemble errors

gistfile1.js

module.exports = function (grunt) {

	grunt.initConfig({
		sass: {
			dist: {
				files: {
					'web/css/screen.css': 'src/sass/screen.sass'
				}
			}
		},
		compass: {
			dist: {
				options: {
                    sassDir: 'src/sass',
                    cssDir: 'web/css',
                    imagesDir: 'web/images'
                }
			}
		},
		watch: {
			sass: {
				files: ['src/sass/*.sass'],
				tasks: ['sass']
			},
            compass: {
                files: ['src/sass/*.sass'],
                tasks: ['compass']
            },
			livereload: {
				// Browser live reloading
				// https://github.com/gruntjs/grunt-contrib-watch#live-reloading
				options: {
					livereload: false
				},
				files: [
					'web/css/screen.css',
					'*.php'
				]
			}
		},
        assemble: {
            options: {
                layout: 'src/layouts/default.hbs',
                partials: 'src/partials/*.hbs',
                flatten: true
            },
            pages: {
                files: {
                    'web/' : ['src/pages/*.hbs']
                }
            },
//            pages: {
//                src: 'src/pages/*.hbs',
//                dest: 'web/'
//            },
//            dist: {
//                files: {
//                    'web/': ['src/pages/*.hbs']
//                }
//            },
            options: {
                collections: [{
                    name: 'post',
                    sortby: 'title',
                    sortorder: 'descending'
                }]
            }
        }
	});

	// Load tasks
	grunt.loadNpmTasks('grunt-sass');
	grunt.loadNpmTasks('grunt-contrib-compass');
	grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('assemble');
    
	// Register tasks
	grunt.registerTask('default', ['sass', 'compass']);
	grunt.registerTask('default', ['watch']);
    grunt.registerTask('default', ['assemble']);

};