userEvent.setup() exists but I'm unable to call it

Reproduction example

import { describe, expect, it } from "vitest";
import userEvent from "@testing-library/user-event";

describe("my test", () => {
  it("should pass", () => {
    console.log(userEvent.setup);
    userEvent.setup();     // <-- fails here
    expect(true).toBe(true);
  });
});

https://github.com/nene/test-userevent

Prerequisites

Sorry, I don't know how to work with tests in codesandbox. Instead I provide a repository:

1. Check out the repo git clone git@github.com:nene/test-userevent.git
2. Install dependencies with npm install
3. Run tests npm test

Expected behavior

Tests execute successfully.

Actual behavior

An error occurs:

 FAIL  src/my.test.ts > my test > should pass
TypeError: Cannot read properties of undefined (reading 'Symbol(Node prepared with document state workarounds)')
 ❯ prepareDocument node_modules/@testing-library/user-event/dist/esm/document/prepareDocument.js:10:17
 ❯ Object.setupMain [as setup] node_modules/@testing-library/user-event/dist/esm/setup/setup.js:52:5
 ❯ src/my.test.ts:7:15
      5|   it("should pass", () => {
      6|     console.log(userEvent.setup);
      7|     userEvent.setup();
       |               ^
      8|     expect(true).toBe(true);
      9|   });

User-event version

14.6.1

Environment

Testing Library framework: @testing-library/dom 10.4.0

JS framework: react 18.3.1 (though not used in test)

Test environment: vitest 3.0.8

DOM implementation: Not sure, Vitest docs say that the default environment is node. I haven't installed any of the optional environments like js-dom or happy-dom.

Additional context

This problem looks similar to #839, but that issue has been fixed, and the workarounds suggested there didn't seem to do anything.

Most strangely, when I console.log(userEvent.setup) it prints:

[Function: setupMain]

Similarly typeof userEvent.setup also tells me that it's a function.

But when I call the function userEvent.setup() I get the error.

I managed to locate this strange Symbol(Node prepared with document state workarounds) inside user-event library. But I have no clue what's going on with that.

Start by cloning nene/test-userevent, installing dependencies, and running npm test to reproduce the failure in src/my.test.ts. Then inspect src/document/prepareDocument.ts at the linked Symbol reference and the reported stack frames; done means the setup call has an established expected behavior in the documented Vitest environment and the regression is covered or clearly explained.