python ensurepip fails due to being unable to find files

[Brian Inglis]

On 2022-03-20 01:42, Brian Inglis wrote:
> On 2022-03-19 22:07, The Other wrote:
>> Using the most recent version of python3 (3.9.10), I was unable to set 
>> up a
>> virtual environment with "python -m venv venv". This was due to the
>> ensurepip stage failing. As such, I tried running ensurepip directly.
>>
>> Output when running "python -m ensurepip":
>>
>> Traceback (most recent call last):
>>    File "/usr/lib/python3.9/runpy.py", line 188, in _run_module_as_main
>>      mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
>>    File "/usr/lib/python3.9/runpy.py", line 147, in _get_module_details
>>      return _get_module_details(pkg_main_name, error)
>>    File "/usr/lib/python3.9/runpy.py", line 111, in _get_module_details
>>      __import__(pkg_name)
>>    File "/usr/lib/python3.9/ensurepip/__init__.py", line 30, in <module>
>>      _SETUPTOOLS_VERSION = _get_most_recent_wheel_version("setuptools")
>>    File "/usr/lib/python3.9/ensurepip/__init__.py", line 27, in
>> _get_most_recent_wheel_version
>>      return str(max(_wheels[pkg], key=distutils.version.LooseVersion))
>> ValueError: max() arg is an empty sequence
>>
>> Looking at the actual code in __init__.py, the function that is failing
>> seems to be constructing a list of .whl files in "_WHEEL_DIR",
>> "/usr/share/python-wheels/", and then returning the latest version of the
>> desired one (setuptools and pip are requested). However, it can't find 
>> any
>> .whl files, and so the max() function fails.
>>
>> My cygwin installation doesn't even seem to have a python-wheels 
>> folder in
>> /usr/share, let alone any .whl files in it. I'm not sure if cygwin
>> downloads and stores .whl files elsewhere, or if they even get downloaded
>> at all.
>>
>> The same error occurs for other versions of python3 I have installed,
>> including python3.8 and python3.6.
>>
>> I have attached my cygcheck.out file as cygcheck.out.txt. My python 3.9
>> install is all OK, though some of the older ones are incomplete for pip.
> 
> Ensure all Cygwin processes are shut down from cmd or Powershell:
> 
>      > tasklist /m cygwin1.dll
>      INFO: No tasks are running which match the specified criteria.
> 
> or usually:
> 
> Image Name                     PID Modules
> ========================= ======== ===========
> bash.exe                      9276 cygwin1.dll
> sh.exe                        3844 cygwin1.dll
> xinit.exe                    10652 cygwin1.dll
> XWin.exe                      3596 cygwin1.dll
> dbus-launch.exe               8104 cygwin1.dll
> dbus-daemon.exe               1512 cygwin1.dll
> gnome-keyring-daemon.exe      6488 cygwin1.dll
> fbxkb.exe                     2196 cygwin1.dll
> xwin-xdg-menu.exe             3372 cygwin1.dll
> gam_server.exe                3580 cygwin1.dll
> pcmanfm.exe                   7496 cygwin1.dll
> mintty.exe                   18284 cygwin1.dll
> bash.exe                      4340 cygwin1.dll
> ssh-agent.exe                14608 cygwin1.dll
> bash.exe                      8384 cygwin1.dll
> 
> but be aware it shows processes, excluding services, using any 
> cygwin1.dll if you have multiple environments installed;
> 
> or check TaskMgr Details Image path name does not show anything running 
> from your Cygwin root bin or related directories.
> 
> Download and run latest Cygwin Setup program.
> 
> Reinstall incomplete or missing python3{,6,7,8,9}-pip latest versions 
> and also install python3{,6,7,8,9}-virtualenv which all preinstall 
> dependencies python-{pip,setuptools,wheel}-wheel.
> 
> Allow the setup postinstall scripts to complete and check for any issues 
> in /var/log/setup.log.full.

Also forgot to suggest python3{,6,7,8,9}-tox which preinstalls 
...-virtualenv and handles managing and using virtual environments.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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