Vite 5.4.0 env var fails when bundling Vite-bundled library

### Describe the bug

This was brought up at https://github.com/vitejs/vite/pull/17648#issuecomment-2278411720

When a library uses Vite (library mode) to bundle and uses env var, the `const __vite_import_meta_env__ = {` may get included in the code. When that happens and we bundle that library in our app, we re-inject the variable declaration again here, which causes a runtime error:

https://github.com/vitejs/vite/blob/fcf50c2e881356ea0d725cc563722712a2bf5695/packages/vite/src/node/plugins/define.ts#L139-L148



### Reproduction

https://github.com/silverwind/vite-import-meta/pull/1

### Steps to reproduce

_No response_

### System Info

```shell
n/a
```


### Used Package Manager

npm

### Logs

<details>
<summary>Click to expand</summary>

```shell
error during build:
[commonjs--resolver] node_modules/lib/dist/index.js (3392:6): Identifier "__vite_import_meta_env__" has already been declared
file: node_modules/lib/dist/index.js:3392:6

3390: const create = (createState) => createState ? createImpl(createState) : createImpl;
3391: const __vite_import_meta_env__ = { "BASE_URL": "/", "DEV": false, "MODE": "production", "PROD": true, "SSR": false };
3392: function createJSONStorage(getStorage, options2) {
            ^
3393:   let storage;
3394:   try {

    at getRollupError (node_modules/vite/node_modules/rollup/dist/es/shared/parseAst.js:392:41)
    at error (node_modules/vite/node_modules/rollup/dist/es/shared/parseAst.js:388:42)
    at Module.error (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13944:16)
    at ModuleScope.addDeclaration (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:7362:21)
    at ModuleScope.addDeclaration (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:12075:22)
    at Identifier.declare (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:6960:39)
    at VariableDeclarator.declareDeclarator (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:10661:17)
    at VariableDeclaration.initialise (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:12343:24)
    at convertNode (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13167:10)
    at convertNodeList (node_modules/vite/node_modules/rollup/dist/es/shared/node-entry.js:13177:34)
```

</details>

### Validations

- [X] Follow our [Code of Conduct](https://github.com/vitejs/vite/blob/main/CODE_OF_CONDUCT.md)
- [X] Read the [Contributing Guidelines](https://github.com/vitejs/vite/blob/main/CONTRIBUTING.md).
- [X] Read the [docs](https://vitejs.dev/guide).
- [X] Check that there isn't [already an issue](https://github.com/vitejs/vite/issues) that reports the same bug to avoid creating a duplicate.
- [X] Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to [vuejs/core](https://github.com/vuejs/core) instead.
- [X] Check that this is a concrete bug. For Q&A open a [GitHub Discussion](https://github.com/vitejs/vite/discussions) or join our [Discord Chat Server](https://chat.vitejs.dev/).
- [X] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.

	// If there's bare `import.meta.env` references, prepend the banner
	if (bareImportMetaEnvRe.test(result.code)) {
	result.code = banner + result.code

	if (result.map) {
	const map = JSON.parse(result.map)
	map.mappings = ';' + map.mappings
	result.map = map
	}
	}

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Vite 5.4.0 env var fails when bundling Vite-bundled library #17874

Describe the bug

Reproduction

Steps to reproduce

System Info

Used Package Manager

Logs

Validations

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development