Vitest browser mode tests do not run when using projects

[Andrei486]

Describe the bug

I am using a monorepo with multiple subpackages. To manage this, I am using vitest, with a configuration at the project root which defines each package as a project. When I run tests (vitest run) from the project root, the non-browser tests run correctly, but browser tests sometimes do not appear and cause the test run to hang. This problem is inconsistent, and usually happens on the first run or after deleting the .vite folder in node_modules (though it can happen other times as well). With a larger number of tests in a non-minimal case I have noticed that sometimes only a few browser tests will be missing at once.

When running vitest run from any of the packages directly, all tests in that package (even browser tests) are executed correctly without fail.

This seems very similar to #3363 which was supposedly closed.

Reproduction

This repo serves as a minimal reproduction: https://github.com/Andrei486/vitest-project-repro.

System Info

System:
    OS: macOS 14.8.2
    CPU: (16) arm64 Apple M3 Max
    Memory: 13.93 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.19.4 - /opt/homebrew/opt/node@20/bin/node
    Yarn: 1.22.22 - /opt/homebrew/bin/yarn
    npm: 10.8.2 - /opt/homebrew/opt/node@20/bin/npm
    pnpm: 9.12.3 - /opt/homebrew/bin/pnpm
  Browsers:
    Chrome: 142.0.7444.176
    Safari: 17.6
  npmPackages:
    @vitest/browser-playwright: latest => 4.0.15 
    vitest: latest => 4.0.15

Used Package Manager

pnpm

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[jaxcksn]

Also experiencing this exact issue, but to add on to it, I do see a lot of zombie processes being created here when it hangs. Works perfectly fine if you don't use projects.

[anilanar]

I'm also experiencing something similar, only when using projects, browser mode causes the whole process to hang, teardown hooks don't trigger, the whole process hangs forever. It doesn't happen always, it happens 50% of the time.

I wonder if this has something to do with browser mode relying on some module-level global state, and then when monorepos are involved, there's a chance that that stateful module is duplicated and different modules see different states, or something along those lines.