Windows embeddable throws FileNotFoundError

Issue

Using the latest (20.15.0) version of virtualenv together with python 3.9 Windows embeddable package throws a FileNotFoundError if calling any module code e.g. python.exe -m virtualenv testEnv.

While following the issue Windows embedable support #1774 and the depending MR Windows embedable support i though it should now be possible to create and handle any venv with a windows embeddable python, but after proceeding the mentioned steps i was still not able to use the virtualenv module. Am i missing any step?

I unzipped the embedded package: https://www.python.org/ftp/python/3.9.13/python-3.9.13-embed-amd64.zip Then I run the get-pip.py: https://bootstrap.pypa.io/get-pip.py Then I uncomment in python39._pth the import statement. Then I add some path to PATH env variable. (add path to python.exe and pip.exe) Then I run pip install virtualenv. Then I tried to call python.exe -m virtualenv testEnv

Note: the unzipped python folder does not contain any DLLs subfolder.

(Tested with latest python 3.9 and 3.10.)

Environment

Provide at least:

• OS:

C:\Users\tester\Downloads\python-3.9.13-embed-amd64>systeminfo

Host Name:                 WIN10
OS Name:                   Microsoft Windows 10 Home
OS Version:                10.0.19043 N/A Build 19043
OS Manufacturer:           Microsoft Corporation
...

• pip list of the host python where virtualenv is installed:

C:\Users\tester\Downloads\python-3.9.13-embed-amd64>python -m pip list
Package      Version
------------ -------
distlib      0.3.4
filelock     3.7.1
pip          22.1.2
platformdirs 2.5.2
setuptools   62.6.0
six          1.16.0
virtualenv   20.15.0
wheel        0.37.1

Output of the virtual environment creation

Make sure to run the creation with -vvv --with-traceback:

C:\Users\tester\Downloads\python-3.9.13-embed-amd64>python.exe -m virtualenv testENV --vvv --with-traceback
Traceback (most recent call last):
  File "runpy.py", line 197, in _run_module_as_main
  File "runpy.py", line 87, in _run_code
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\__main__.py", line 80, in <module>
    run_with_catch()  # pragma: no cov
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\__main__.py", line 65, in run_with_catch
    run(args, options, env)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\__main__.py", line 18, in run
    session = cli_run(args, options, env)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\run\__init__.py", line 30, in cli_run
    of_session = session_via_cli(args, options, setup_logging, env)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\run\__init__.py", line 48, in session_via_cli
    parser, elements = build_parser(args, options, setup_logging, env)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\run\__init__.py", line 74, in build_parser
    CreatorSelector(interpreter, parser),
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\run\plugin\creators.py", line 15, in __init__
    creators, self.key_to_meta, self.describe, self.builtin_key = self.for_interpreter(interpreter)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\run\plugin\creators.py", line 25, in for_interpreter
    meta = creator_class.can_create(interpreter)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\create\via_global_ref\builtin\via_global_self_do.py", line 34, in can_create
    cls._sources_can_be_applied(interpreter, meta)
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\create\via_global_ref\builtin\via_global_self_do.py", line 39, in _sources_can_be_applied
    for src in cls.sources(interpreter):
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\create\via_global_ref\builtin\cpython\cpython3.py", line 67, in sources
    for ref in refs:
  File "C:\Users\tester\Downloads\python-3.9.13-embed-amd64\lib\site-packages\virtualenv\create\via_global_ref\builtin\cpython\cpython3.py", line 98, in dll_and_pyd
    for file in folder.iterdir():
  File "pathlib.py", line 1160, in iterdir
FileNotFoundError: [WinError 3] The system cannot find the path specified: 'C:\\Users\\tester\\Downloads\\python-3.9.13-embed-amd64\\DLLs'

[reksar]

Creating an empty DLLs folder should fix the issue.

[reksar]

If you know what you do and it just works - why not?

Most use-cases is simple and portable Python environment. I think closest alternative is PyPy (if you don’t pay attention that this is not CPython), but nuget Python package can be too. But both of these alternatives have stdlib venv module, while embedded Python does not. And only virtualenv can help in this case.

Using pip to manage dependencies as for a regular Python installation is not supported with this distribution

but we make pip work

It’s worth pointing out that the embedded distribution doesn’t include the stdlib venv module

and we install virtualenv through pip

Are we insane? Yes! Does it hurt someone?)