Bug: Lost error messages from Server side

[present-g]

React version:19

Steps To Reproduce

1. Throw any error from the Server Component.
2. Check the message in the Error Boundary

The current behavior

In error.tsx (Next.js error boundary), instead of the error message, we get the stub: "An error occurred in the Server Components render. The specific message is omitted in production builds to avoid leaking sensitive details. A digest property is included on this error instance which may provide additional details about the nature of the error."

The expected behavior

We often need to read the specific error message that we throw from the server, so I suggest adding an optional parameter to show the messages.

For example:

// Server Component
throw new Error('Some custom error', { cause: 'TopLevelError' });

// https://github.com/facebook/react/blob/443b7ff2a8437f7736491ae7136c21d75d5a2019/packages/react-client/src/ReactFlightClient.js#L3000
// ReactFlightClient.js

if (__DEV__ || errorInfo.cause === 'TopLevelError') {
        error = resolveErrorDev(response, errorInfo);
      } else {
        error = resolveErrorProd(response);
      }

[present-g]

Similar issue on Next's repo

vercel/next.js#71101

[Natthachai-arm]

React version:19

Steps To Reproduce

1. Throw any error from the Server Component.
2. Check the message in the Error Boundary

The current behavior

In error.tsx (Next.js error boundary), instead of the error message, we get the stub: "An error occurred in the Server Components render. The specific message is omitted in production builds to avoid leaking sensitive details. A digest property is included on this error instance which may provide additional details about the nature of the error."

The expected behavior

We often need to read the specific error message that we throw from the server, so I suggest adding an optional parameter to show the messages.

For example:

// Server Component
throw new Error('Some custom error', { cause: 'TopLevelError' });
//

react/packages/react-client/src/ReactFlightClient.js

Line 3000 in 443b7ff

if (__DEV__) {

// ReactFlightClient.js

if (DEV || errorInfo.cause === 'TopLevelError') {
error = resolveErrorDev(response, errorInfo);
} else {
error = resolveErrorProd(response);
}

[present-g]

As a temporary solution, we can use something like this, but I really hope that we will receive an official way to save error messages from the server side.

vercel/next.js#71101 (comment)