Bug: `@license` header in React 18 bundles contains `vundefined`

[Andarist]

Can be checked on top of the files here:

• https://unpkg.com/react@18.0.0-rc.0-next-aa8f2bdbc-20211215/cjs/react.development.js
• https://unpkg.com/react@18.0.0-rc.0/cjs/react.development.js

I've wanted to fix this quickly... but it turns out that your whole build pipeline is a little bit convoluted so it ain't a 5 min fix. I could still work on this but I would need some pointers as to what is the preferred fix.

From what I understand - this broken version is read here:

react/scripts/rollup/wrappers.js

Line 6 in ceee524

const reactVersion = require('../../package.json').version;

but the root package.json doesn't contain a version. It seems that scripts are updating "root" package.json here:

react/scripts/release/utils.js

Lines 231 to 238 in ceee524

	// Update the root package.json.
	// This is required to pass a later version check script.
	{
	const packageJSONPath = join(cwd, 'package.json');
	const packageJSON = await readJson(packageJSONPath);
	packageJSON.version = version;
	await writeJson(packageJSONPath, packageJSON, {spaces: 2});
	}

but this only happens for the temp dir created during the release as 2 scripts are using copyRepoToTempDirectory.

I think the scripts should be run in the context of those temp dirs and that could potentially fix the problem (maybe they already are but something else is broken? I didn't yet confirm this).

The additional problem is that this wouldn't fix the local yarn build as this doesn't update this root package.json version at all.

[bvaughn]

@Andarist The build scripts were refactored a couple of months ago to remove a build-info.json file. Maybe this regressed then? Not sure.

One quick fix might be to just update scripts/rollup/wrappers.js to use a different package.json to read the version from. Like packages/react-dom/package.json? Would that work?

[vitaliemiron]

I'll take it.