What is so special about Python 2.6+?

PyInstaller since version 1.5

Starting with release 1.5 PyInstaller fully supports Python 2.6+ on all supported platforms.

On Windows, no separate CRT installation is required: the one-file or one-dir executables generated by PyInstaller? will work on vanilla Windows installations (Windows 2000 or later), without a separate CRT installation step required.

PyInstaller up to version 1.4

PyInstaller up to version 1.5 fully support Python 2.6+ under Linux and Mac OSX.

On Windows, things are different. The official python.org distribution of Python 2.6+ switched from Visual Studio 2003 to Visual Studio 2008. As a consequence, all binaries are now compiled against the newer MSVCR90.DLL CRT library, which requires the usage of the so-called manifests (metadata in XML format usually embedded within the DLL). This basically means that:

• PyInstaller must add a lot of new code to extract and parse manifests from DLLs, so to chase dependencies among modules
• Since it is not sufficient anymore to just copy MSVCR90.DLL into the target directory (thanks to the so-called SxS mess), PyInstaller also needs to bundle special manifests so that the libraries are dynamically found and loaded. Moreover, these manifests might need to be altered even within third-party binary libraries (.pyd files).

This has been implemented in PyInstaller 1.5. Please update to this version (or a newer one) when packaging Python 2.6+ on Windows.