This problem should be introduced in Rspack 1.0.0-beta.0. If there is a reproduction, it will be very helpful to fix the bug.

Hello @abenhamdine. Please provide a reproduction repository or online demo. For background, see Why reproductions are required. Thanks ❤️

I fail to reproduce the error in a basic project : it works fine with a simple react project with App.tsx and one line of code.

So the issue is probably triggered by a combination of modules/configs/whatever but I can't figure out where it comes from

I tried to replace import.meta.env with process.env but same result : ReferenceError: process is not defined

Any hint/help would be useful !

You can try to remove all the source code in your project and only keep the related lines of code. Then check what will happen.

You can try to remove all the source code in your project and only keep the related lines of code. Then check what will happen.

Good idea : I succeed in reproducing the bug : https://github.com/abenhamdine/repro-rsbuild-beta6

Please pay attention that you have to be in the folder /client to install and start the app

This undefined issue is introduced in Rspack's web-infra-dev/rspack#7229. The current output is align with webpack v5.

• Input:

if (import.meta.env.PUBLIC_SENTRY_DSN) {

• Output (Rspack 1.0 alpha):

if (undefined) {

• Output (Rspack 1.0 beta.0 and webpack v5):

if (/* unsupported import.meta.env.PUBLIC_SENTRY_DSN */ undefined.PUBLIC_SENTRY_DSN) {

• Output (Vite v5)

var define_import_meta_env_default = { BASE_URL: "/", MODE: "production", DEV: false, PROD: true, SSR: false };
if (define_import_meta_env_default.PUBLIC_SENTRY_DSN) {
  console.log(1);
}

@LingyuCoder Is undefined.PUBLIC_SENTRY_DSN expected? This will cause a runtime error, perhaps we should use a more robust output.

@abenhamdine PUBLIC_SENTRY_DSN is not defined in your .env.development file.

If this value is empty in development, it is recommended to define it as PUBLIC_SENTRY_DSN="" rather than leaving it undefined.

@abenhamdine PUBLIC_SENTRY_DSN is not defined in your .env.development file.

If this value is empty in development, it is recommended to define it as PUBLIC_SENTRY_DSN="" rather than leaving it undefined.

Oh yes you're right, it solves the issues, thx !

it is recommended to define it as PUBLIC_SENTRY_DSN="" rather than leaving it undefined.

I would even say it's now required to define it because of this new behaviour.

Is undefined.PUBLIC_SENTRY_DSN expected? This will cause a runtime error, perhaps we should use a more robust output.

Just aligned with webpack. Perhaps this needs futher discussion.

I understand that Rspack and webpack do not support import.meta.env by default because it is not part of the specification.

The question is, why replace import.meta.env with undefined instead of leaving it as is?

As the issue was labelled with need reproduction, but no response in 5 days. This issue will be closed. Feel free to comment and reopen it if you have any further questions. For background, see Why reproductions are required.

由于该 issue 被标记为 "需要重现"，但在 5 天内没有回应，因此该 issue 将被关闭。如果你有任何进一步的问题，请随时发表评论并重新打开该 issue。背景请参考 为什么需要最小重现。

Tracking in: web-infra-dev/rspack#7364