Unable to build website

[d4nyll]

Do you want to request a feature or report a bug?
🐛 Bug 🐛

What is the current behavior?

Steps to reproduce (following instructions from the Contribution Guidelines:

$ git clone [email protected]:facebook/jest.git
$ cd jest
$ git reset --hard 3d84d75374d23b035cc87cba14afaa7b761273b7
$ yarn
$ cd website
$ yarn
$ yarn run build
yarn run v1.3.2
warning package.json: No license field
$ docusaurus-build
Extracting translateable strings from files...
Loading translation files...
Generating Metadata for Docs....
Generating Metadata for Docs....
Generating Metadata for Docs....
generate.js triggered...
Generating Metadata for Docs....
feed.js triggered...
feed.js triggered...
sitemap.js triggered...
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. Checkthe render method of `Index`.
    in Index
    in div (created by Site)
    in body (created by Site)
    in html (created by Site)
    in Site
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. Checkthe render method of `Index`.
    in Index
    in div (created by Site)
    in body (created by Site)
    in html (created by Site)
    in Site
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. Checkthe render method of `Index`.
    in Index
    in div (created by Site)
    in body (created by Site)
    in html (created by Site)
    in Site
Warning: React.createElement: type is invalid -- expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. Checkthe render method of `Index`.
    in Index
    in div (created by Site)
    in body (created by Site)
    in html (created by Site)
    in Site
Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `Index`. See https://fb.me/react-warning-keys for more information.
    in a (created by Index)
    in Index
    in div (created by Site)
    in body (created by Site)
    in html (created by Site)
    in Site
/home/dli/playground/jest/website/node_modules/fbjs/lib/invariant.js:49
    throw error;
    ^

Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in. Check the render method of `Index`.
    at invariant (/home/dli/playground/jest/website/node_modules/fbjs/lib/invariant.js:42:15)
    at instantiateReactComponent (/home/dli/playground/jest/website/node_modules/react-dom/lib/instantiateReactComponent.js:72:56)
    at instantiateChild (/home/dli/playground/jest/website/node_modules/react-dom/lib/ReactChildReconciler.js:42:28)
    at /home/dli/playground/jest/website/node_modules/react-dom/lib/ReactChildReconciler.js:69:16
    at traverseAllChildrenImpl (/home/dli/playground/jest/website/node_modules/react-dom/lib/traverseAllChildren.js:75:5)
    at traverseAllChildrenImpl (/home/dli/playground/jest/website/node_modules/react-dom/lib/traverseAllChildren.js:91:23)
    at traverseAllChildren (/home/dli/playground/jest/website/node_modules/react-dom/lib/traverseAllChildren.js:170:10)
    at Object.instantiateChildren (/home/dli/playground/jest/website/node_modules/react-dom/lib/ReactChildReconciler.js:68:7)
    at ReactDOMComponent._reconcilerInstantiateChildren (/home/dli/playground/jest/website/node_modules/react-dom/lib/ReactMultiChild.js:183:41)
    at ReactDOMComponent.mountChildren (/home/dli/playground/jest/website/node_modules/react-dom/lib/ReactMultiChild.js:222:27)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

What is the expected behavior?

The build should succeed and when I run yarn run start I should see the website.

Please provide your exact Jest configuration and mention your Jest, node,
yarn/npm version and operating system.

$ uname -a
Linux [omitted] 4.13.0-16-lowlatency #19-Ubuntu SMP PREEMPT [date] x86_64 x86_64 x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 17.10
Release:        17.10
Codename:       artful
$ node -v
v8.9.0
$ yarn -v
1.3.2

[tryzniak]

It probably can be closed now because of #4924

[github-actions]

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