grpython use posix prefix scheme

[maitbot]

Recently in Debian's pthon3.10 the default scheme for sysconfig
changed from 'posix_prefix' to 'posix_local'. GrPython.cmake
expects the 'posix_prefix' behavior. So explicity use it.

Signed-off-by: A. Maitland Bottoms bottoms@debian.org

---

name: grpython use posix prefix scheme
about: GrPython.cmake
title: ''
labels: ''
assignees: ''

---

Pull Request Details

Description

Install path changed to /usr/local with python3.10 - even though the desire
is to set the install directories using gnuradio's cmake paths.

Related Issue

Debian bug:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1008854

Which blocks/areas does this affect?

Not only gnuradio itself - but every OOT project that inherits GrPython.cmake.

Testing Done

Debian builds as part of the python3.10-default transition.

Checklist

• I have read the CONTRIBUTING document.
• I have squashed my commits to have one significant change per commit.
• I have signed my commits before making this PR
• My code follows the code style of this project. See GREP1.md.
• I have updated the documentation where necessary.
• I have added tests to cover my changes, and all previous tests pass.

[willcode]

Since prefix_posix is the default scheme
https://docs.python.org/3/library/sysconfig.html#installation-paths
and we are not currently specifying a scheme, this seems safe.
@ryanvolz can you verify that this is ok for Windows, since there are separate schemes listed for nt.

[ryanvolz]

Hmm, clearly there are no issues with the conda builds because the recipe sets GR_PYTHON_PATH (and that's still true for the conda-forge packages), so I don't expect to personally see any problems because of this change. But I do wonder about other theoretical Windows users since this does change the default scheme from "nt" to "posix_prefix" in that case. (It looks like there will be a new scheme option with Python 3.11 that would do what @mait wants but also keep the nt scheme on Windows, "venv", but obviously it would be a while until we could use that.) Maybe a ternary expression like "posix_prefix" if os.name != "nt" else "nt" would result in minimal change for users?

[drmpeg]

Since Ubuntu 22.04 is using Python 3.10, this patch is pretty much necessary now. Otherwise, the PYTHONPATH (<install_prefix>/local/lib/python3.10/dist-packages) is dramatically different than before.

[drmpeg]

Tested on Ubuntu 22.04.

[mormj]

Let's go ahead and merge this on main but hold off on backport, given the Windows concerns.