pip download resolves wrong platform (bitness) on Windows

[lefi7z]

Description

When downloading binary packages on Windows, pip seems to look for the wrong suffix: -win32 instead of the expected -amd64 (see below).

(test) C:\venv>python -VV
Python 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 23:03:10) [MSC v.1916 64 bit (AMD64)]

(test) C:\venv>python -m pip list
Package    Version
---------- -------
pip        21.1.1
setuptools 41.2.0

(test) C:\venv>python -m pip download -d C:/Temp --only-binary :all: numpy
Collecting numpy
  Using cached numpy-1.20.2-cp38-cp38-win32.whl (11.4 MB)
Saved c:\temp\numpy-1.20.2-cp38-cp38-win32.whl
Successfully downloaded numpy

(test) C:\venv>

Expected behavior

No response

pip version

21.1.1

Python version

3.8.2

OS

Windows 64bit

How to Reproduce

python -m pip download -d C:/Temp --only-binary :all: numpy

Output

Collecting numpy
  Using cached numpy-1.20.2-cp38-cp38-win32.whl

Code of Conduct

• I agree to follow the PSF Code of Conduct.

[sbidoul]

This looks similar to #8649 ?

[lefi7z]

Yes, thank you! According to the mentioned issue, I checked the return value of distutils.utils.get_platform() and found that it gives the wrong result in a Developer Command Prompt:

$ python -c "import distutils.util; print(distutils.util.get_platform())"
win32

$ python -c "import distutils.util; print(distutils.util.get_host_platform())"
win-amd64

$ set VS
VS160COMNTOOLS=C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\Common7\Tools\
VSCMD_ARG_app_plat=Desktop
VSCMD_ARG_HOST_ARCH=x86
VSCMD_ARG_TGT_ARCH=x86
VSCMD_VER=16.9.3
VSINSTALLDIR=C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\

I would have never figured this out, believing that this information should be built into the binary at compile time! Well, using a vanilla Command Prompt does the trick.

[uranusjr]

Closing as duplicate then.