msetup: fix regression under py3.13 causing profile.runctx to not write locals()

"PEP 667: Consistent views of namespaces" caused locals() to be
inconsistent between uses since it is now created afresh every time you
invoke it and writes to it are dropped. `sys._getframe().f_locals` is
equivalent but preserves writes (it doesn't create a new dict) and
unfortunately doesn't help at all as it's documented to be a private
implementation detail of CPython that "should be used for internal and
specialized purposes only".

Work around this by saving locals to a variable reference and both
passing it into runctx and reusing it in lookups of the result. This
works okay for both new and older versions of python.

Per the documentation for locals():

> The contents of this dictionary should not be modified; changes may
> not affect the values of local and free variables used by the
> interpreter.

So... lesson learned? :) This was introduced in commit
c34ee374a77fb2dffff90364506ac0cbbb1f00de; before that, we still used
locals() but only to pass local variables *in*.

Bug: https://github.com/python/cpython/pull/115153
1 file changed
tree: 2dcb0d4d4f673512b74d26c27f85a1d86ef1ec11
  1. .github/
  2. ci/
  3. cross/
  4. data/
  5. docs/
  6. graphics/
  7. man/
  8. manual tests/
  9. mesonbuild/
  10. packaging/
  11. test cases/
  12. tools/
  13. unittests/
  14. .editorconfig
  15. .flake8
  16. .gitattributes
  17. .gitignore
  18. .mailmap
  19. .mypy.ini
  20. .pylintrc
  21. azure-pipelines.yml
  22. CODEOWNERS
  23. contributing.md
  24. COPYING
  25. MANIFEST.in
  26. meson.py
  27. pyproject.toml
  28. README.md
  29. run_cross_test.py
  30. run_format_tests.py
  31. run_meson_command_tests.py
  32. run_mypy.py
  33. run_project_tests.py
  34. run_single_test.py
  35. run_tests.py
  36. run_unittests.py
  37. setup.cfg
  38. setup.py
  39. skip_ci.py
README.md

Status

PyPI Build Status Codecov

Dependencies

  • Python (version 3.7 or newer)
  • Ninja (version 1.8.2 or newer)

Latest Meson version supporting previous Python versions:

  • Python 3.6: 0.61.5
  • Python 3.5: 0.56.2
  • Python 3.4: 0.45.1

Installing from source

Meson is available on PyPi, so it can be installed with pip3 install meson. The exact command to type to install with pip can vary between systems, be sure to use the Python 3 version of pip.

If you wish you can install it locally with the standard Python command:

python3 -m pip install meson

For builds using Ninja, Ninja can be downloaded directly from Ninja GitHub release page or via PyPi

python3 -m pip install ninja

More on Installing Meson build can be found at the getting meson page.

Creating a standalone script

Meson can be run as a Python zip app. To generate the executable run the following command:

./packaging/create_zipapp.py --outfile meson.pyz --interpreter '/usr/bin/env python3' <source checkout>

Running

Meson requires that you have a source directory and a build directory and that these two are different. In your source root must exist a file called meson.build. To generate the build system run this command:

meson setup <source directory> <build directory>

Depending on how you obtained Meson the command might also be called meson.py instead of plain meson. In the rest of this document we are going to use the latter form.

You can omit either of the two directories, and Meson will substitute the current directory and autodetect what you mean. This allows you to do things like this:

cd <source root>
meson setup builddir

To compile, cd into your build directory and type ninja. To run unit tests, type ninja test.

More on running Meson build system commands can be found at the running meson page or by typing meson --help.

Contributing

We love code contributions. See the contribution page on the website for details.

IRC

The channel to use is #mesonbuild either via Matrix (web interface) or OFTC IRC.

Further info

More information about the Meson build system can be found at the project's home page.

Meson is a registered trademark of Jussi Pakkanen.