create-react-app: Webpack warning: There is another module with an equal name when case is ignored

I’m using 0.4.1 version and I get:

Warning in (webpack)/buildin/module.js
There is another module with an equal name when case is ignored.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Rename module if multiple modules are expected or use equal casing if one module is expected.

Warning in ./~/react-scripts/~/webpack/buildin/module.js
There is another module with an equal name when case is ignored.
This can lead to unexpected behavior when compiling on a filesystem with other case-semantic.
Rename module if multiple modules are expected or use equal casing if one module is expected.

when I run the app by npm start

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 16 (11 by maintainers)

Most upvoted comments

I was able to reproduce with the following steps:

On a Windows machine, create a new directory ‘TEST’. (Doesn’t matter what you name it, just put in caps somewhere).
In your CLI navigate to your directory and create-react-app app-test within it.
npm start
Terminate the development server
In some other window, without closing your currently open CLI (explorer, another CLI environment), rename ‘TEST’ to ‘test’. (Change the case to its opposite case, whatever you named it).
Return to your original CLI and run npm start to receive these errors.

This happened to me earlier today while I was doing some file cleanup while also developing. I was able to clear them out by cd.. out back to the root path (just before ‘TEST’) and navigating back in, then running npm start. Not sure what could cause it to happen consistently, but it might be related to some file structure changes during development.

jemgraves on Apr 23, 2017