In Developer Guide says:

"If you don’t have easy access to a command line, you can run the test suite from a Python or IDLE shell:

>>> from test import autotest"

But I can't run test from IDLE:

Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    from test import autotest
  File "D:\repos\cpython\Lib\test\autotest.py", line 5, in <module>
    main()
  File "D:\repos\cpython\Lib\test\libregrtest\main.py", line 585, in main
    Regrtest().main(tests=tests, **kwargs)
  File "D:\repos\cpython\Lib\test\libregrtest\main.py", line 510, in main
    self._main(tests, kwargs)
  File "D:\repos\cpython\Lib\test\libregrtest\main.py", line 524, in _main
    setup_tests(self.ns)
  File "D:\repos\cpython\Lib\test\libregrtest\setup.py", line 18, in setup_tests
    faulthandler.enable(all_threads=True)
io.UnsupportedOperation: fileno

If I understand it correct, this behavior is reasonable (issues 3003 and 25588).
Maybe it's worth to remove words about running from IDLE. Or in case if it's possible to run such tests add some words about it.