astral-sh/python-build-standalone 20260924 on GitHub

Updates

The 'full' distributions now include an annotation file which indicates CPython tests which are known to fail or be flaky.
On Linux, the _tkinter module includes a origin relative RPATH which points to the location of libtcl/tk.
Windows debug distributions are available for all Python versions. These distribution require the runtime libraries provided by Visual Studio.
Linux and macOS LTO optimized builds use Full-LTO on all Python version. Previously some versions used ThinLTO.
The Windows CPython 3.10, 3.11, 3.12 and 3.13 distributions all use Tcl/Tk 8.6.15. A separate zlib DLL is included.
The Windows CPython 3.14 and 3.15 distributions include some missing Tcl/Tk 9.0 files.
On Windows the PYTHON.json files now correctly records Tcl/Tk information.
A man page for python is now included with the Linux and macOS distributions.

A Debian 13 image with a Jessie/Stretch sysroot is used to build the Linux x86-64 and aarch64 distributions.
On Windows, the Visual Studio environment is activated within the build script, activation is not longer required prior to starting the script.
Visual Studio 2026 is used for the Windows ARM64 builds. These builds still use the v143 platform toolset. Native ARM64 compilers are used to build CPython and most dependencies.
Various minor changes to the CI setup.

Documentation was converted to markdown and is available at https://docs.astral.sh/python-build-standalone/. This material will be updated over the coming weeks.
An action runs the CPython test suite on demand against existing distributions to validate the bundled annotation.

Full Changelog: 2026090...2026092