Utopian React is React, except for one change: we modify the production build of React to include un-minified error messages. Because our editor and projects are in the same document, and because React can only have one version per document, projects have to use the same build of React as we use in the editor. We use the production build because this means faster performance for users, but we also want users to be able to read un-minified error messages. So we have changed the build process to keep unminified error messages.

The results of the build are then pushed to utopia-react, and utopia-react-dom, and aliased to react and react-dom in the editor.

1. Find the tag or commit you want to build from the main React repo
2. Make a pr against master in this repo.
3. Make sure the changes haven't messed up the lines changed in the build script at /scripts/rollup/build.js. It should roughly keep the noMinify: true settings the same as they were from this change: https://github.com/concrete-utopia/react/commit/c96e246bb3620ed3b86d92ef725c7f1a3cffcbb2.
4. Merge that pull request

1. Check out concrete-utopia/react on your local computer.
2. Install with $ yarn and then build React using $ yarn build react,react-dom
3. Go make a cup of tea. Unless you are Sean, building will take quite a few minutes.

1. Open up the react and react-dom directories from utopia/editor/node_modules.
2. For each directory delete the contents with the exception of package.json.
3. Update the version field in both react and react-dom to the target version number.
4. In react-dom's package.json only: update the peer dependency to point to "^XX.X.X", where XX.X.X is the current target version. Note the leading circumflex.
5. Take the built react and react-dom directories from react/build/node_modules/ and respectively overwrite the contents (save the package.jsons) of the utopia/editor/node_modules/react and utopia/editor/node_modules/react-dom directories.
6. Run npm publish in each directory. This publishes them to utopia-react and utopia-react-dom (contact @alecmolloy for write access to these packages.)

You can confirm error messages have properly been compiled without minification simply by breaking React with e.g. a call to useEffect() outside a function component in the code editor, while running react in performance mode.