Bug: Can't really access component stack `errorInfo.componentStack` on server

[brillout]

React version: 19.2.2

On the server-side, upon a boundary error, the component stack can be accessed via onError(err, errorInfo) => errorInfo.componentStack but this has limited (no?) value because the general recommendation is to swallow boundary errors and let the client-side throw the error instead (if it fails again on the client-side).

The real value AFAICT would be to access the component stack upon shell errors, but I don't see a way to access error.componentStack:

• The onShellError() callback of renderToPipeableStream() doesn't receive errorInfo.componentStack.
• Shell errors thrown while renderToReadableStream() also seem to be missing errorInfo.componentStack.

Context

I'm the author of react-streaming which powers vike-react amongst others.