v2_dev crashes with React17 + ESM

[xHomu]

What version of Remix are you using?

v1.19.1

Are all your remix dependencies & dev-dependencies using the same version?

• Yes

Steps to Reproduce

• Demo Repo: https://github.com/xHomu/remix-v2-server/tree/esm-server-react17
• Initial Report on Discord: https://discordapp.com/channels/770287896669978684/1135991368230109194

Change any of the following, and the template runs as expected:

• Update react and react-dom to "^1.18.2"
• Comment out v2_dev in remix.config.js
• Go with CJS instead: https://github.com/xHomu/remix-v2-server/tree/cjs-server.js-react17

I thought it might have been the default entry.server and entry.client, so I went ahead and grabbed the old react17 versions of the entry files, no luck: https://github.com/remix-run/remix/blob/d86cc1ed904ce98a04db3f9048f99ef6e710e9a4/templates/express/app/entry.server.tsx

Expected Behavior

Dev server runs, hmr working as expect (with React 17 caveats).

Actual Behavior

This error seems specific to the React 17 + ESM + v2 Dev Server combination, which results in the following errors:

[xHomu]

@WillSmithTE

[jacob-ebey]

React 17 does not have an exports map, this means if you want to use react 17 in an ESM runtime you'll have to import the /server deep import as react-dom/server.js.

[pcattori]

We're dropping support for React 17 in Remix v2, so not planning to address this. That said, just because it isn't officially supported doesn't mean it definitely won't work. I wouldn't be surprised if some app/entry.server.tsx could be crafted to get React 17 running

[ryanflorence]

Thanks Pedro. For a little more context on this decision there's a lot of good stuff we'll be bringing into v2 with v3_flags, and we don't want React 17 support making it all very difficult.