21 March 2016

Nuitka Release 0.5.20

This is to inform you about the new stable release of Nuitka. It is the extremely compatible Python compiler, “download now”.

This release is mostly about catching up with issues. Most address standalone problems with special modules, but there are also some general compatibility corrections, as well as important fixes for Python3.5 and coroutines and to improve compatibility with special Python variants like Anaconda under the Windows system.

Bug Fixes

  • Standalone Python3.5: The _decimal module at least is using a __name__ that doesn’t match the name at load time, causing programs that use it to crash.

  • Compatibility: For Python3.3 the __loader__ attribute is now set in all cases, and it needs to have a __module__ attribute. This makes inspection as done by e.g. flask working.

  • Standalone: Added missing hidden dependencies for Tkinter module, adding support for this to work properly.

  • Windows: Detecting the Python DLL and EXE used at compile time and preserving this information use during backend compilation. This should make sure we use the proper ones, and avoids hacks for specific Python variants, enhancing the support for Anaconda, WinPython, and CPython installations.

  • Windows: The --python-debug flag now properly detects if the run time is supporting things and error exits if it’s not available. For a CPython3.5 installation, it will switch between debug and non-debug Python binaries and DLLs.

  • Standalone: Added plug-in for the Pwm package to properly combine it into a single file, suitable for distribution.

  • Standalone: Packages from standard library, e.g. xml now have proper __path__ as a list and not as a string value, which breaks code of e.g. PyXML.

  • Standalone: Added missing dependency of twisted.protocols.tls.

  • Python3.5: When finalizing coroutines that were not finished, a corruption of its reference count could happen under some circumstances.

  • Standalone: Added missing DLL dependency of the uuid module at run time, which uses ctypes to load it.

New Features

  • Added support for Anaconda Python on this Linux. Both accelerated and standalone mode work now.

  • Added support for standalone mode on FreeBSD.

  • The plug-in framework was expanded with new features to allow addressing some specific issues.


  • Moved memory related stuff to dedicated utils package nuitka.utils.MemoryUsage as part of an effort to have more topical modules.

  • Plugins how have a dedicated module through which the core accesses the API, which was partially cleaned up.

  • No more “early” and “late” import detections for standalone mode. We now scan everything at the start.


This release focused on expanding plugins. These were then used to enhance the success of standalone compatibility. Eventually this should lead to a finished and documented plug-in API, which will open up the Nuitka core to easier hacks and more user contribution for these topics.