WP Build: Page crashes with "Element type is invalid" error.

[dhasilva]

Description

After this PR wp-build pages are breaking with the following message:

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, or you might have mixed up default and named imports.

Check the render method of `RootSinglePage`.

Step-by-step reproduction instructions

1. Go to a page that uses wp-build.
2. Check the error.

A simple plugin where this can be tested: https://github.com/dhasilva/minimal-wp-build-test (ignore the "No Gutenberg" thing, it was meant to debug another issue, but serves to test this as well)

Screenshots, screen recording, code snippet

Environment info

• Gutenberg trunk

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[ellatrix]

This sounds like either an issue with wp-build or npm packages to me (but we haven't published stable npm packages since that commit).

But it also seems like you're overriding the private API's global? Is that expected? https://github.com/dhasilva/minimal-wp-build-test/blob/trunk/build/scripts/private-apis/index.js

I don't know anything about wp-build, would love to have help from others familiar with it.

[ellatrix]

Could be related to #73379, which started bundling private-apis in wp-build, cc @youknowriad

[simison]

Could it be some interplay between the two changes? We've been working with #73379 in the WP build for a while now already, and it works fine. With Gutenberg enabled, things work as long as I revert #75387 locally, but otherwise it breaks.

[ellatrix]

Well yes, it's because there's been no private API additions since then so the file is the same as core's

[ellatrix]

#75460 could fix it I think, could you test it?

[simison]

@ellatrix Tested with both minimal setup and Jetpack Forms (feature flag add_filter('jetpack_forms_alpha', '__return_true');) and seeing the same issue still.