Unable to start new app

[Conrad2134]

Note from Maintainers

Newly created applications experienced a brief disruption between 8:15 PM - 9:15 PM (EST). The issue is now resolved.

Please delete the node_modules directory and then run npm install.
If using yarn, you only need to run yarn upgrade.

---

Can you reproduce the problem with latest npm?

Yes

Description

I created a new app with create-react-app and I'm not able to run it. I can create a production build just fine and run that, but the development build doesn't work.

Actual behavior

Here is the error I'm receiving in the terminal / browser:

Failed to compile.

Error in ./src/index.js
Module build failed: TypeError: /home/connor/git/Wakonda/src/index.js: Cannot read property 'scope' of undefined
 @ multi main

And here's what I see when I open the console:

Uncaught Error: Cannot find module "/home/connor/git/cra-bug/src/index.js"
    at webpackMissingModule (bootstrap 2a26695…:578)
    at Object.<anonymous> (bootstrap 2a26695…:578)
    at __webpack_require__ (bootstrap 2a26695…:555)
    at bootstrap 2a26695…:578
    at bootstrap 2a26695…:578

Environment

Run these commands in the project folder and fill in their results:

1. npm ls react-scripts (if you haven’t ejected):
   └── react-scripts@0.9.0
2. node -v:
   v7.5.0
3. npm -v:
   4.1.2

If it makes any difference, I was using Yarn, but I also tested installing dependencies via npm and got the same issue.

Edit: I also tried this in Windows 10, and I receive the same error.

Then, specify:

1. Operating system: Elementary OS (Linux)
2. Browser and version: Chrome 56

Reproducible Demo

https://github.com/Conrad2134/cra-bug

[ColinRTaylor]

I'm getting the same error.

Environment:
node v7.2.1
OSX El Capitan 10.11.5

I think it has to do with the version of babel-core used.

I fixed it by:

1. Ejecting
2. Upgrading babel-core to 6.23.0

[thevarunraja]

I'm getting the same error

Environment:
node -v
v7.4.0

npm -v
4.2.0

Operating System: macOS Sierra v10.12.3

[ajeremiaspb]

I had the same error too.
Just update babel in your project using this command:

npm install --save-dev babel-core

References:

ModuleBuildError: Module build failed: TypeError: Cannot read property 'scope' of undefined
Fix bug - undefined reference for export declaration

[Conrad2134]

@ajeremias - that did work for me, thanks for the tip! 👍

If anyone needs a temporary solution - that's it.

[davidfekke]

This is broken for me as well.

Error in ./src/index.js
Module build failed: TypeError: /Users/********/Documents/node/projects/hello-world/src/index.js: Cannot read property 'scope' of undefined
@ multi main

[genma123]

@ajeremias - that worked for me, too! Didn't need to eject.

[existentialism]

We inadvertently released a backwards incompatible change in babel-traverse.

We just reverted it and released a fix (6.23.1) that should fix this issue. Please reinstall deps. Sorry for the inconvenience!

[glazzari]

It could be related to babel/babel#5305.

[Timer]

Sorry for the trouble everyone! Perhaps now is the time to reignite our Yarn discussions.

[Conrad2134]

Thanks for looking into it!

[Timer]

I've opened an issue about this here so we can try to prevent this from happening in the future: #1551