Two computers running cygwin; on one python venv sets up fine and on the other an error

[Soren]

Doug, thank you very much for your reply. I will try to answer adequately.

On Sun, Jun 28, 2026 at 8:56 PM Doug Henderson via Cygwin <cygwin@cygwin.com>
wrote:

> On Sun, Jun 28, 2026 at 11:51 AM Andrey Repin via Cygwin <
> cygwin@cygwin.com>
> wrote:
>
> > Greetings, Soren!
> >
> > > Hello Cygwinstas,
> >
> > > As in the Subject: I have two systems with Windows 11 and with Cygwin
> > > installed. I am attempting to reproduce the execution of a series of
> > steps
> > > leading to meson being installed on the second computer, so I can do
> some
> > > code building. I've tried it multiple times and keep getting this
> failure
> > > message:
> >
> > > $ type -p python3 && python3 --version
> > > /usr/bin/python3
> > > Python 3.12.12
> > > $ python3 -m venv ~/Devel/python.venv/beleriand
> > > Error: Command
> > > '['/cygdrive/c/Users/soren/Devel/python.venv/beleriand/bin/python',
> '-m',
> > > 'ensurepip', '--upgrade', '--default-pip']' returned non-zero exit
> > status 1.
> >
> > Most commonly, this means something wrong in the base system behavior.
> > Check the `mount` output, try `rebase-trigger full` and make sure no
> Cygwin
> > processes are running when you run setup.exe afterward.
> >
> > > On the first system, where the virtual env works fine, I see this:
> >
> > > $ type -p python3 && python3 --version
> > > /usr/bin/python3
> > > Python 3.12.12
> >
> > > It's the same version of python, yep. What could be wrong? TIA.
>
>
> Two things come to mind.
>
> * Check that your alternates configurations are identical on both systems.
>
> Sorry, I need some expansion on that -- "alternates configuration"? I am
not sure what that means.


> * check that you are not attempting (directly or indirectly) to use pip to
> upgrade a package which is provide by a python package installed using the
> Cygwin setup.exe app. If pip is not installed, you will need to use the
> Cygwin setup installer for pip.


Using cygcheck I ascertained that  pip is not installed by setup.exe.
Ok. I can do that.  ... I did that now. Using cygcheck I now see this
report:
Installed package:
------------------

Name        : python3-pip
Version     : 26.0.1
Release     : 1
Architecture: noarch
Size        : 116 (116 B)
Categories  : Python Virtual
Source      : python-pip-26.0.1-1-src.tar.xz
Summary     : Python package installation tool
Description :
The python3-pip virtual package. Selecting this package for installation
will cause the python39-pip package to be installed.




> Try using "python -m venv --without-pip VENV"


I will try that. ... It runs with no output. Exit status is "0".

BTW: It is not clear what the current directory is when you run the error
> command. Was that the complete error message? Was there not also a
> traceback, possibly with messages before the traceback?
>

The cwd is /cygdrive/C/Devel/python.venv

That was the complete error message. I still get that same message if I try
to set up the venv by not using "--without-pip".

I offer thanks to Doug and also Andrey who I didn't reply to yet.

  - Soren