`unit-test` builder causes the following error: `The entry point "vitest" cannot be marked as external`

[yjaaidi]

Command

test

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

angular/angular-build-builds@50039a7

Description

This build introduces the bug: angular/angular-build-builds@425fabb

It seems to be related to this refactoring: 4cf1aa3

Minimal Reproduction

Tests won't start in browser mode and cause the provided error.

Might be a false positive given I am using the builds.

Exception or Error

Vitest caught 1 unhandled error during the test run.
This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Unhandled Error ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
{
  detail: undefined,
  id: '',
  location: null,
  notes: [],
  pluginName: '',
  text: 'The entry point "vitest" cannot be marked as external',
  type: 'Unhandled Error',
  stacks: []
}

Your Environment

Angular CLI       : 21.1.0-next.0+sha-21a486b
Angular           : 21.0.0-rc.1
Node.js           : 24.8.0
Package Manager   : pnpm 10.20.0
Operating System  : darwin arm64

┌───────────────────────────┬───────────────────────────┬──────────────────────────────────────────────────────────────────────────────┐
│ Package                   │ Installed Version         │ Requested Version                                                            │
├───────────────────────────┼───────────────────────────┼──────────────────────────────────────────────────────────────────────────────┤
│ @angular/build            │ 21.1.0-next.0+sha-377780a │ github:angular/angular-build-builds#425fabbbd2c332d8d49338894d7ed15222eb41d7 │
│ @angular/cli              │ 21.1.0-next.0+sha-21a486b │ workspace:*                                                                  │
│ @angular/common           │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/compiler         │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/compiler-cli     │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/core             │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/forms            │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/platform-browser │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ @angular/router           │ 21.0.0-rc.1               │ 21.0.0-rc.1                                                                  │
│ rxjs                      │ 7.8.2                     │ ^7.8.1                                                                       │
│ typescript                │ 5.9.3                     │ ~5.9.2                                                                       │
│ vitest                    │ 4.0.8                     │ 4.0.8

Anything else relevant?

No response

[jnizet]

This also happens with the just-released rc2 version.

[clydin]

We are unable to reproduce the issue as described. Please provide a minimal reproduction demonstrating the problem so that we can further investigate.

[yjaaidi]

I just tried with rc2 and I can't reproduce either.

@jnizet did you try on a freshly created workspace? or by cleaning up .angular & node_modules/.vite. I can't see how this can be related to the cache but who knows 🤷🏻‍♂️