Official Install on Windows PowerShell failed on FileNotFoundError

Start with install-poetry.py, especially Installer.run, Installer.install, make_env, and VirtualEnvironment.make, then reproduce the official PowerShell command with Python 3.9.6 and 3.8.10 on Windows. Check the virtual-environment creation path and subprocess failure; done means the documented installation completes without FileNotFoundError and Poetry is restored after uninstall.

I've been trying to update my 1.1.13 poetry install to 1.2.2 using the official doc but it failed.

PS D:\Downloads>(Invoke-WebRequest -Uri https://install.python-poetry.org -UseBasicParsing).Content | python3 -
Retrieving Poetry metadata

# Welcome to Poetry!

This will download and install the latest version of Poetry,
a dependency and package manager for Python.

It will add the `poetry` command to Poetry's bin directory, located at:

D:\AppData\Roaming\Python\Scripts

You can uninstall at any time by executing this script with the --uninstall option,
and these changes will be reverted.

Installing Poetry (1.2.2)
Installing Poetry (1.2.2): Saving existing environment
Installing Poetry (1.2.2): Creating environment
Installing Poetry (1.2.2): An error occurred. Removing partial environment.
Installing Poetry (1.2.2): Restoring previously saved environment.
Traceback (most recent call last):
  File "D:\Downloads\install-poetry.py", line 940, in <module>
    sys.exit(main())
  File "D:\Downloads\install-poetry.py", line 919, in main
    return installer.run()
  File "D:\Downloads\install-poetry.py", line 550, in run
    self.install(version)
  File "D:\Downloads\install-poetry.py", line 571, in install
    with self.make_env(version) as env:
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\contextlib.py", line 117, in __enter__
    return next(self.gen)
  File "D:\Downloads\install-poetry.py", line 643, in make_env
    raise e
  File "D:\Downloads\install-poetry.py", line 629, in make_env
    yield VirtualEnvironment.make(env_path)
  File "D:\Downloads\install-poetry.py", line 319, in make
    builder.create(target)
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\venv\__init__.py", line 75, in create
    self._setup_pip(context)
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\venv\__init__.py", line 298, in _setup_pip
    subprocess.check_output(cmd, stderr=subprocess.STDOUT)
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\subprocess.py", line 424, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\subprocess.py", line 505, in run
    with Popen(*popenargs, **kwargs) as process:
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\subprocess.py", line 951, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "D:\.pyenv\pyenv-win\versions\3.9.6\lib\subprocess.py", line 1420, in _execute_child
    hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
FileNotFoundError: [WinError 2] Le fichier spécifié est introuvable

and the error same occurs after poetry uninstall with both python 3.9.6 and python3.8.10

I now don't have poetry anymore on my computer 😢