使用laravel-elixir-images，错误优化图像

Question

最近我正在使用laravel 5.4并尝试使用laravel-elixir-images来优化一些图像。

安装软件包并执行后，错误显示：

 /../node_modules/underscore-deep-extend/index.js:102
        Object.keys(source).forEach(procMain);
               ^

TypeError: Cannot convert undefined or null to object
    at extendObject (/../node_modules/underscore-deep-extend/index.js:102:16)
    at Function._.each._.forEach (/../node_modules/underscore/underscore.js:153:9)
    at Function.underscoreDeepExtend [as deepExtend] (/../node_modules/underscore-deep-extend/in
dex.js:105:5)
    at Function.<anonymous> (/../node_modules/laravel-elixir-images/index.js:31:23)
    at Function.<anonymous> (/../node_modules/laravel-elixir/dist/bootstrap/EnableExtension.js:1
6:18)
    at mix (/../gulpfile.js:20:9)
    at global.Elixir (/../node_modules/laravel-elixir/dist/index.js:21:5)
    at Object.<anonymous> (/../gulpfile.js:17:1)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)

任何人都像我一样面对类似的问题吗？有什么建议吗？