Describe the bug

When running Vitest in run-mode and doing a non-graceful exit with CTRL+c, the forks workers are sometimes left running in the background even though main process exits.

In my case I'm not spawning any additional processes during the test run. Graceful exit in watch-mode kills the worker properly.

Reproduction

Reproduces the issue but is not (yet) minimal one:

• Git checkout https://github.com/AriPerkkio/ast-v8-to-istanbul
• pnpm install; pnpm build
• pnpm run test test/convert.e2e.ts
• Hit CTRL+c
• Check running node processes, look for the forks.js from Vitest

System Info

System:
    OS: macOS 15.6.1
    CPU: (8) arm64 Apple M2
    Memory: 444.67 MB / 16.00 GB
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 22.18.0 - /Users/ari/.nvm/versions/node/v22.18.0/bin/node
    npm: 11.6.0 - /Users/ari/.nvm/versions/node/v22.18.0/bin/npm
    pnpm: 10.23.0 - /Users/ari/.nvm/versions/node/v22.18.0/bin/pnpm
    bun: 1.2.21 - /Users/ari/.bun/bin/bun
    Deno: 2.3.6 - /Users/ari/.deno/bin/deno
  Browsers:
    Brave Browser: 131.1.73.101
    Chrome: 142.0.7444.176
    Firefox: 135.0
    Safari: 18.6
  npmPackages:
    @vitejs/plugin-vue: ^6.0.2 => 6.0.2 
    @vitest/coverage-istanbul: ^4.0.13 => 4.0.13 
    @vitest/coverage-v8: ^4.0.13 => 4.0.13 
    vite: ^7.2.4 => 7.2.4 
    vitest: ^4.0.13 => 4.0.13

Used Package Manager

pnpm

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• The provided reproduction is a minimal reproducible example of the bug.