gruntjs - Compass and Susy require a different version of Sass -

i working on website , want use susy compass. using grunt too. when run grunt task error:

denniss-macbook-pro:portfolio dennis$ grunt --trace running "compass:dev" (compass) task gem::loaderror on line ["1990"] of /system/library/frameworks/ruby.framework/versions/2.0/usr/lib/ruby/2.0.0/rubygems/specification.rb: unable activate susy-2.1.1, because sass-3.2.17 conflicts sass (~> 3.3.0) run --trace see full backtrace warning: ↑ use --force continue.  aborted due warnings. 

this grunt file:

module.exports = function(grunt) { grunt.initconfig({ pkg: grunt.file.readjson('package.json'),  watch: {   options: {     livereload: true   },   css: {     files: ['_sass/*.{scss,sass}'],     tasks: ['compass:dev']   },   js: {     files: ['js/*.js'],     tasks: ['uglify']   } },  compass: {   options: {     require: 'susy'   },   dev: {     options: {       sassdir: ['_sass'],       cssdir: ['css'],       environment: 'development',     }   },    production: {     options: {       sassdir: ['_sass'],       cssdir: ['css'],       outputstyle: 'compressed',       environment: 'production',     }   } },  uglify: {   all: {     files: {       'js/main.min.js': [       'js/libs/*.js',       'js/src/*.js'       ]     }   } },  connect: {   port: 8000 }   });    grunt.loadnpmtasks('grunt-contrib-compass');   grunt.loadnpmtasks('grunt-contrib-watch');   grunt.loadnpmtasks('grunt-contrib-uglify');   grunt.loadnpmtasks('grunt-contrib-connect');    grunt.registertask('default', ['compass:dev', 'uglify','connect', 'watch']);   grunt.registertask('production', ['compass:production', 'uglify']); } 

i don't know do, in advance!

there problem dependencies incompatible: susy 2.0.0 depends on sass ~> 3.3.0 compass 0.12.3 depends on sass = 3.2.14

you can list gems by:

gem list 

try this:

gem install compass --pre 

this should work.