18 May 2013

Nuitka Release 0.4.3

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

This release expands the reach of Nuitka substantially, as new platforms and compilers are now supported. A lot of polish has been applied. Under the hood there is the continued and in-progress effort to implement SSA form in Nuitka.

New Features

  • Support for new compiler: Microsoft Visual C++.

    You can now use Visual Studio 2008 or Visual Studio 2010 for compiling under Windows.

  • Support for NetBSD.

    Nuitka works for at least NetBSD 6.0, older versions may or may not work. This required fixing bugs in the generic “fibers” implementation.

  • Support for Python3 under Windows too.

    Nuitka uses Scons to build the generated C++ files. Unfortunately it requires Python2 to execute, which is not readily available to call from Python3. It now guesses the default installation paths of CPython 2.7 or CPython 2.6 and it will use it for running Scons instead. You have to install it to C:\Python26 or C:\Python27 for Nuitka to be able to find it.

  • Enhanced Python 3.3 compatibility.

    The support the newest version of Python has been extended, improving compatibility for many minor corner cases.

  • Added warning when a user compiles a module and executes it immediately when that references __name__.

    Because very likely the intention was to create an executable. And esp. if there is code like this:

    if __name__ == "__main__":

    In module mode, Nuitka will optimize it away, and nothing will happen on execution. This is because the command

    nuitka --execute module

    is behavioral more like

    python -c "import module"

    and that was a trap for new users.

  • All Linux architectures are now supported. Due to changes in how evaluation order is enforced, we don’t have to implement for specific architectures anymore.

Bug Fixes

  • Dictionary creation was not fully compatible.

    As revealed by using Nuitka with CPython3.3, the order in which dictionaries are to be populated needs to be reversed, i.e. CPython adds the last item first. We didn’t observe this before, and it’s likely the new dictionary implementation that finds it.

    Given that hash randomization makes dictionaries item order undetermined anyway, this is more an issue of testing.

  • Evaluation order for arguments of calls was not effectively enforced. It is now done in a standards compliant and therefore fully portable way. The compilers and platforms so far supported were not affected, but the newly supported Visual Studio C++ compiler was.

  • Using a __future__ import inside a function was giving an assertion, instead of the proper syntax error.

  • Python3: Do not set the attributes sys.exc_type, sys.exc_value, sys.exc_traceback.

  • Python3: Annotations of function worked only as long as their definition was not referring to local variables.


  • Calls with no positional arguments are now using the faster call methods.

    The generated C++ code was using the () constant at call site, when doing calls that use no positional arguments, which is of course useless.

  • For Windows now uses OS “Fibers” for Nuitka “Fibers”.

    Using threads for fibers was causing only overhead and with this API, MSVC had less issues too.


  • Accepting Donations via Paypal, please support funding travels, website, etc.

  • The User Manual has been updated with new content. We now do support Visual Studio, documented the required LLVM version for clang, Win64 and modules may include modules too, etc. Lots of information was no longer accurate and has been updated.

  • The Changelog has been improved for consistency, wordings, and styles.

  • Nuitka is now available on the social code platforms as well

    • Bitbucket (since removed)

    • GitHub

    • Gitorious (since discontinued)

    • Google Code (since discontinued)

  • Removed clean-up.sh, which is practically useless, as tests now clean up after themselves reasonably, and with git clean -dfx working better.

  • Removed “create-environment.sh” script, which was only setting the PATH variable, which is not necessary.

  • Added check-with-pylint --emacs option to make output its work with Emacs compilation mode, to allow easier fixing of warnings from PyLint.

  • Documentation is formatted for 80 columns now, source code will gradually aim at it too. So far 90 columns were used, and up to 100 tolerated.


  • Removed useless manifest and resource file creation under Windows.

    Turns out this is no longer needed at all. Either CPython, MinGW, or Windows improved to no longer need it.

  • PyLint massive cleanups and annotations bringing down the number of warnings by a lot.

  • Avoid use of strings and built-ins as run time pre-computed constants that are not needed for specific Python versions, or Nuitka modes.

  • Do not track needed tuple, list, and dict creation code variants in context, but e.g. in nuitka.codegen.TupleCodes module instead.

  • Introduced an “internal” module to host the complex call helper functions, instead of just adding it to any module that first uses it.

New Tests

  • Added basic tests for order evaluation, where there currently were None.

  • Added support for “2to3” execution under Windows too, so we can run tests for Python3 installations too.


The release is clearly major step ahead. The new platform support triggered a whole range of improvements, and means this is truly complete now.

Also there is very much polish in this release, reducing the number of warnings, updated documentation, the only thing really missing is visible progress with optimization.