08 March 2014

Nuitka Release 0.5.1

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

This release brings corrections and major improvements to how standalone mode performs. Much of it was contributed via patches and bug reports.

Bug Fixes

  • There was a crash when using next on a non-iterable. Fixed in already.

  • Module names with special characters not allowed in C identifiers were not fully supported. Fixed in already.

  • Name mangling for classes with leading underscores was not removing them from resulting attribute names. This broke at __slots__ with private attributes for such classes. Fixed in already.

  • Standalone on Windows might need “cp430” encoding. Fixed in already.

  • Standalone mode didn’t work with lxml.etree due to lack of hard coded dependencies. When a shared library imports things, Nuitka cannot detect it easily.

  • Wasn’t working on macOS 64 bits due to using Linux 64 bits specific code. Fixed in already.

  • On MinGW the constants blob was not properly linked on some installations, this is now done differently (see below).

New Features

  • Memory usages are now traced with --show-progress allowing us to trace where things go wrong.


  • Standalone mode now includes standard library as bytecode by default. This is workaround scalability issues with many constants from many modules. Future releases are going to undo it.

  • On Windows the constants blob is now stored as a resource, avoiding compilation via C code for MSVC as well. MinGW was changed to use the same code.

New Tests

  • Expanded test coverage for “standalone mode” demonstrating usage of “hex” encoding, PySide, and PyGtk packages.


This release is mostly an interim maintenance release for standalone. Major changes that provide optimization beyond that, termed “C-ish code generation” are delayed for future releases.

This release makes standalone practical which is an important point. Instead of hour long compilation, even for small programs, we are down to less than a minute.

The solution of the scalability issues with many constants from many modules will be top priority going forward. Since they are about how even single use constants are created all in one place, this will be easy, but as large changes are happening in “C-ish code generation”, we are waiting for these to complete.