       realAtomBuild = fs.realpathSync @root + '/.atom-build.json'
       delete require.cache[realAtomBuild]
       build = require realAtomBuild
-      [ exec, env, args, cwd ] = [ build.cmd, build.env, build.args, build.cwd ]
+      [ exec, env, args, cwd, sh ] = [ build.cmd, build.env, build.args, build.cwd, build.sh ]
+      sh = true if not sh?
 
     if !exec && fs.existsSync @root + '/package.json'
       realPackage = fs.realpathSync @root + '/package.json'

    args = _.map args, @replace

    @child = child_process.spawn(
      '/bin/sh',
      [ '-c', [cmd.exec].concat(args).join(' ') ],
      { cwd : @replace cmd.cwd, env: env }
    )


      exec: exec,
      env: env || {},
      args: args || [],
      cwd: cwd || @root,
      sh: sh
    }

  replace: (value) ->
