Module not found @material-ui/core/ThemeProvider when minimizing bundle size in create react app

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

I get

Module not found: Can't resolve '@material-ui/core/ThemeProvider'

Expected Behavior 🤔

I don’t expect any errors.

Steps to Reproduce 🕹

Since this is a bug related to the project setup then I can’t make a codesandbox for it

Steps:

1. npx create-react-app my_app --template typescript
2. install material core 5.0.0-alpha.13
3. npm add -D babel-plugin-transform-imports react-app-rewired customize-cra
4. Update package.json and create .babelrc.js, config-overrides.js files as outlined in the docs.
5. create source content as in this example.

Context 🔦

Your Environment 🌎

Tech	Version
Material-UI	v5.0.0-alpha.13
React	v16.14.0
Browser
TypeScript	v4.0.3
etc.

[oliviertassinari]

@eps1lon From what I understand, the tweet mentions that there are a few modules that need an exception because they don’t follow the folder convention (import x from '@material-ui/core/x'). The relevant link from the gist the tweet has: https://gist.github.com/developit/037baaec2a0a1e64e628c84fdd5c1107#file-babel-plugin-transform-mui-imports-js-L19

[eps1lon]

So you are suggesting not using option 2 for now?

I suggest using option 1 only for @material-ui/icons only where it has the biggest benefit. Anything not using babel plugins should be safe regardless.