python39/PACKAGING-NOTES

Notes for packagers of Python3
==============================

0. Faster build turnaround
--------------------------

By default, python builds with profile-guided optimization. This needs
an additional run of the test suite and it is generally slow.
PGO build takes around 50 minutes.

For development, use "--without profileopt" option to disable PGO. This
shortens the build time to ~5 minutes including test suite.

1. import_failed.map
----------------------

This is a mechanism installed as part of python3-base, that places shim modules
on python's path (through a generated zzzz-import-failed-hooks.pth file, so that
it is imported as much at the end as makes sense; and an _import_failed subdir
of /usr/lib/pythonX.Y). Then when the user tries to import a module that is part
of a subpackage, the ImportError will contain a helpful message telling them
which missing subpackage to install.

This can sometimes cause problems on non-standard configurations, if the pth
gets included too early (for instance if you are using a script to include all
pths by hand in some strange order). Just something to look out for.
- Add CVE-2025-4516-DecodeError-handler.patch fixing CVE-2025-4516 (bsc#1243273) blocking DecodeError handling vulnerability, which could lead to DoS. %%files. - Use python3 modules to build the documentation. * Support Expat >= 2.4.5 - allow build with Sphinx >= 3.x * remove importlib_resources and importlib-metadata - bpo-41304: Fixes python3x._pth being ignored on Windows, caused - bpo-29778: Ensure python3.dll is loaded from correct locations - bpo-39603: Prevent http header injection by rejecting control “__setattr__” in a multi-inheritance setup and - bpo-41247: Always cache the running loop holder when running - bpo-41252: Fix incorrect refcounting in - bpo-41215: Use non-NULL default values in the PEG parser - bpo-41218: Python 3.8.3 had a regression where compiling with ast.PyCF_ALLOW_TOP_LEVEL_AWAIT would - bpo-41175: Guard against a NULL pointer dereference within - bpo-39960: The “hackcheck” that prevents sneaking around a type’s __setattr__() by calling the superclass method was - bpo-41288: Unpickling invalid NEWOBJ_EX opcode with the - bpo-39017: Avoid infinite loop when reading specially crafted - bpo-41207: In distutils.spawn, restore expectation that - bpo-41194: Fix a crash in the _ast module: it can no longer be - bpo-39384: Fixed email.contentmanager to allow set_content() to set a - bpo-41300: Save files with non-ascii chars. - bpo-37765: Add keywords to module name completion list. - bpo-40170: Revert PyType_HasFeature() change: it reads again directly the PyTypeObject.tp_flags member when the limited C API is not used, rather than always calling OBS-URL: https://build.opensuse.org/package/show/devel:languages:python:Factory/python39?expand=0&rev=231 2025-05-30 16:01:02 +00:00			`Notes for packagers of Python3`
			`==============================`

			`0. Faster build turnaround`
			`--------------------------`

			`By default, python builds with profile-guided optimization. This needs`
			`an additional run of the test suite and it is generally slow.`
			`PGO build takes around 50 minutes.`

			`For development, use "--without profileopt" option to disable PGO. This`
			`shortens the build time to ~5 minutes including test suite.`

			`1. import_failed.map`
			`----------------------`

			`This is a mechanism installed as part of python3-base, that places shim modules`
			`on python's path (through a generated zzzz-import-failed-hooks.pth file, so that`
			`it is imported as much at the end as makes sense; and an _import_failed subdir`
			`of /usr/lib/pythonX.Y). Then when the user tries to import a module that is part`
			`of a subpackage, the ImportError will contain a helpful message telling them`
			`which missing subpackage to install.`

			`This can sometimes cause problems on non-standard configurations, if the pth`
			`gets included too early (for instance if you are using a script to include all`
			`pths by hand in some strange order). Just something to look out for.`