Notes.md

Python 3.5

• Build from a path that doesn't contain spaces. Otherwise you may get an error 9009 when executing gendef.
• Install HTML Help Compiler.
• Install Windows SDK 10.0.15063.468, which is the latest version that is compatible with Tcl/Tk 8.6.4 (https://core.tcl-lang.org/tk/tktview/9e31fd9449). It is OK to have a newer Windows SDK installed as well, in which case Windows SDK 10.0.15063.468 is used to build Tcl/Tk only while the newest installed Windows SDK is used for other components.
• Install Sphinx 1.7.9 for 3.5.5-3.5.7 or Sphinx 1.8.5 for 3.5.8-3.5.10 into a Python 3.6 venv and set SPHINXBUILD to the path to sphinx-build.exe.
• Apply support-vs-2026-1.patch to support building with Visual Studio 2026 using the v145 toolset and to avoid an issue where Tcl/Tk is not compatible with the Windows 11 SDK (derived from https://github.com/python/cpython/commit/0e4ad88ff8956d9289ab0a1314636ac15b374459, https://github.com/python/cpython/commit/eede148296bf3b4578b92ed6a07f2733a0f1c341, https://github.com/python/cpython/commit/c05e491a69df3fe0a8be91eeddd330792ada6755, https://github.com/python/cpython/commit/45faf151c693b6f13f78926761caea6df7242024, and https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply get-dependencies-from-github.patch to get external dependencies from GitHub instead of the old SVN repository at https://svn.python.org/projects/python/externals, which no longer exists (derived from https://github.com/python/cpython/commit/04431c926a88be433203f89e3577addd0d41b602). Dependencies are pulled from https://github.com/python/cpython-source-deps and https://github.com/python/cpython-bin-deps. However, some old versions of dependencies predate the migration to GitHub, so they are instead pulled from https://github.com/adang1345/cpython-source-deps and https://github.com/adang1345/cpython-bin-deps.
• Apply build-full-installer-1.patch to include debug symbols and debug binaries in the installer.
• Run buildrelease.bat.

Python 3.6

• Build from a path that doesn't contain spaces. Otherwise you may get an error 9009 when executing gendef.
• Install HTML Help Compiler.
• Install Windows SDK 10.0.15063.468, which is the latest version that is compatible with Tcl/Tk 8.6.4 (https://core.tcl-lang.org/tk/tktview/9e31fd9449). It is OK to have a newer Windows SDK installed as well, in which case Windows SDK 10.0.15063.468 is used to build Tcl/Tk only while the newest installed Windows SDK is used for other components.
• Install Sphinx 2.4.5 to a Python 3.6 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-2.patch to support building with Visual Studio 2026 using the v145 toolset and the Windows 11 SDK. Also avoid an issue where Tcl/Tk is not compatible with the Windows 11 SDK. (Derived from https://github.com/python/cpython/commit/30f4fa456ef626ad7a92759f492ec7a268f7af4e, https://github.com/python/cpython/commit/c83ec055a09137e4b24f70e3bb5f887dc0ae6e8e, https://github.com/python/cpython/commit/cba5ddf088683859dd022d04cb3726d56f5f0297, https://github.com/python/cpython/commit/df4852cbe4b757e8b79506d73a09ec8a1b595970, https://github.com/python/cpython/commit/0e4ad88ff8956d9289ab0a1314636ac15b374459, https://github.com/python/cpython/commit/eede148296bf3b4578b92ed6a07f2733a0f1c341, https://github.com/python/cpython/commit/c05e491a69df3fe0a8be91eeddd330792ada6755, https://github.com/python/cpython/commit/45faf151c693b6f13f78926761caea6df7242024, and https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583. Also used the suggestion at python/cpython#84133 (comment).)
• Apply fix-hhc.patch to fix error calling the HTML Help Compiler (python/cpython#79555).
• Apply fix-htmlhelp.patch to fix error in documentation build (python/cpython#90621).
• Apply build-full-installer-1.patch to include debug symbols and debug binaries in the installer.
• Apply fix-test_winconsole.patch to fix a hang during PGO profile generation (python/cpython#85895).
• Run buildrelease.bat.

Python 3.7

• Build from a path that doesn't contain spaces. Otherwise you may get an error 9009 when executing gendef.
• Install HTML Help Compiler.
• Install Sphinx 2.4.5 to a Python 3.6 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-3.patch to support building with Visual Studio 2026 using the v145 toolset and the Windows 11 SDK (derived from https://github.com/python/cpython/commit/45faf151c693b6f13f78926761caea6df7242024 and https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-2.patch to include debug symbols and debug binaries in the installer.
• Apply fix-htmlhelp.patch to fix error in documentation build (python/cpython#90621).
• Apply fix-test_winconsole.patch to fix a hang during PGO profile generation (python/cpython#85895).
• Apply fix-ucrt-1.patch for 3.7.13 or higher to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.8

• Build from a path that doesn't contain spaces. Otherwise you may get an error 9009 when executing gendef.
• Install HTML Help Compiler.
• Install Sphinx 2.4.5 to a Python 3.6 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-4.patch for 3.8.11-3.8.12 or support-vs-2026-5.patch for 3.8.13 or higher to support building with Visual Studio 2026 using the v145 toolset and the Windows 11 SDK (derived from https://github.com/python/cpython/commit/45faf151c693b6f13f78926761caea6df7242024 and https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply fix-libffi-1.patch for 3.8.11 or fix-libffi-2.patch for 3.8.12 to avoid error where libffi-7.lib can't be found (python/cpython#27982).
• Apply build-full-installer-2.patch to include debug symbols and debug binaries in the installer.
• Apply fix-htmlhelp.patch to fix error in documentation build (python/cpython#90621).
• Apply fix-chm.patch to fix formatting errors in the .chm help file (python/cpython#91207).
• Apply fix-vcruntime-threads.patch to fix python/cpython#115167.
• Apply fix-ucrt-1.patch for 3.8.13 or higher to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.9

• Install HTML Help Compiler.
• Install Sphinx 3.5.4 to a Python 3.6 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-6.patch to support building with Visual Studio 2026 using the v145 toolset and the Windows 11 SDK (derived from https://github.com/python/cpython/commit/45faf151c693b6f13f78926761caea6df7242024 and https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-3.patch to include debug symbols, debug binaries, and the Universal CRT in the installer.
• Apply fix-guid.patch to fix python/cpython#96729.
• Apply fix-chm.patch to fix formatting errors in the .chm help file (python/cpython#91207).
• Apply fix-vcruntime-threads.patch to fix python/cpython#115167.
• Apply fix-ucrt-1.patch to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.10

• Install HTML Help Compiler.
• Install Sphinx 3.5.4 to a Python 3.6 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-7.patch to support building with Visual Studio 2026 using the v145 toolset (derived from https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-4.patch to include debug symbols, debug binaries, and the Universal CRT in the installer.
• Apply fix-vcruntime-threads.patch to fix python/cpython#115167.
• Apply fix-ucrt-1.patch to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.11

• Create a Python 3.10 venv and set PYTHON to the location of the Python executable. If building multiple versions in succession, create a fresh new venv with 3.11.10 and 3.11.12.
• Apply support-vs-2026-8.patch for 3.11.10-3.11.17 or support-vs-2026-9.patch for 3.11.18 or higher to support building with Visual Studio 2026 using the v145 toolset (derived from https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-5.patch to include debug symbols, debug binaries, and the Universal CRT in the installer.
• Apply enable-arm64-1.patch to enable ARM64 builds. This also fixes python/cpython#123915 and python/cpython#150400.
• Apply fix-ucrt-2.patch to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.12

• Create a Python 3.11 venv and set PYTHON to the location of the Python executable. If building multiple versions in succession, create a fresh new venv with 3.12.11, 3.12.12, and 3.12.13.
• Apply support-vs-2026-8.patch to support building with Visual Studio 2026 using the v145 toolset (derived from https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-5.patch to include debug symbols, debug binaries, and the Universal CRT in the installer.
• Apply enable-arm64-2.patch to enable ARM64 builds. This also fixes python/cpython#150400.
• Apply fix-ucrt-2.patch to fix error installing Universal C Runtime (python/cpython#138896).
• Run buildrelease.bat.

Python 3.13

• Create a Python 3.12 venv and set PYTHON to the location of the Python executable.
• Apply support-vs-2026-9.patch to support building with Visual Studio 2026 using the v145 toolset (derived from https://github.com/python/cpython/commit/c06f4f43015528db45bd6b44b46c057d88b38583).
• Apply build-full-installer-6.patch to include debug symbols, debug binaries, the Universal CRT, and the experimental free-threaded build in the installer.
• Apply enable-arm64-3.patch to enable ARM64 builds. This also fixes python/cpython#150400.
• Run buildrelease.bat.