Your webpack configuration is not creating a manifest

https://github.com/rails/webpacker/issues/2825

启动rails视图页面，出现了报错：

Webpacker can't find application.css in /Users/sammy/workspace/abright/public/packs/manifest.json. Possible causes:
1. You want to set webpacker.yml value of compile to true for your environment
unless you are using the `webpack -w` or the webpack-dev-server.
2. webpack has not yet re-run to reflect updates.
3. You have misconfigured Webpacker's config/webpacker.yml file.
4. Your webpack configuration is not creating a manifest.
Your manifest contains:
{ }

解决：

rails webpacker:compile

还是不能解决：

app/javascript/packs/application.js

没有这个文件，那么对js的引用就注释掉，就可以了。