28 March 2018

Nuitka Release 0.5.29

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

This release comes with a lot of improvements across the board. A lot of focus has been givevn to the packaging side of Nuitka, but also there is a lot of compatibility work.

Bug Fixes

  • Windows: When using Scons for Python3 and Scons for Python2 on the same build directory, a warning would be given about the need to migrate. Make the Scons cache directory use the Python ABI version as a key too, to avoid these issues. Fixed in already.

  • Windows: Fixup for Python3 and Scons no more generating the MinGW64 import library for Python anymore properly. Was only working if cached from a previous install of Nuitka. Fixed in already.

  • Plugins: Made the data files plugin mandatory and added support for the scrapy package needs.

  • Fix, added implicit dependencies for pkg_resources.external package. Fixed in already.

  • Fix, an import of x.y where this was not a package didn’t cause the package x to be included.

  • Standalone: Added support for six.moves and requests.packages meta imports, these cause hidden implicit imports, that are now properly handled.

  • Standalone: Patch the __file__ value for technical bytecode modules loaded during Python library initialization in a more compatible way.

  • Standalone: Extension modules when loaded might actually raise legit errors, e.g. ImportError of another module, don’t make those into SystemError anymore.

  • Python3.2: The __package__ of sub-packages was wrong, which could cause issues when doing relative imports in that sub-package.

  • Python3: Contractions in a finally clause could crash the compiler.

  • Fix, unused closure variables could lead to a crash in they were passed to a nested function.

  • Linux: Standalone dependency analysis could enter an endless recursion in case of cyclic dependencies.

  • Python3.6: Async generation expressions need to return a None value too.

  • Python3.4: Fix, __spec__ is a package attribute and not a built-in value.

New Features

  • It is now possible to run Nuitka with some_python_you_choose -m nuitka ... and therefore know exactly which Python installation is going to be used. It does of course need Nuitka installed for this to work. This mechanism is going to replace the --python-version mechanism in the future.

  • There are dedicated runners for Python3, simply use nuitka3 or nuitka3-run to execute Nuitka if your code is Python3 code.

  • Added warning for implicit exception raises due to mismatch in unpacking length. These are statically detected, but so far were not warned about.

  • Added cache for depends.exe results. This speeds up standalone mode again as some of these calls were really slow.

  • The import tracer is more robust against recursion and works with Python3 now.

  • Added an option to assume yes for downloading questions. The currently only enables the download of depends.exe and is intended for CI servers.

  • There is now a report file for scons, which records the values used to run things, this could be useful for debugging.

  • Nuitka now registers with distutils and can be used with bdist_wheel directly, but this lacks documentation and tests. Many improvements in the distutils build.


  • Forward propagate compile time constants even if they are only potential usages. This is actually the case where this makes the most sense, as it might remove its use entirely from the branches that do not use it.

  • Avoid extra copy of finally code. The cloning operation takes time and memory, and this shaved of 0.3% of Nuitka memory usage, as these can also become dangling.

  • Class dictionaries are now proper dictionaries in optimization, using some dedicated code for name lookups that are transformed to dedicated locals dictionary or mapping (Python3) accesses. This currently does not fully optimize, but will in coming releases, and saves about 25% of memory compared to the old code.

  • Treating module attributes __package__, __loader__, __file__, and __spec__ with dedicated nodes, that allow or forbid optimization dependent on usage.

  • Python3.6: Async generator expressions were not working fully, become more compatible.

  • Fix, using super inside a contraction could crash the compiler.

  • Fix, also accept __new__ as properly decorated in case it’s a classmethod too.

  • Fix, removed obsolete --nofreeze-stdlib which only complicated using the --recurse-stdlib which should be used instead.


  • The nuitka Python package is now installed into the public namespace and used from there. There are distinct copies to be installed for both Python2 and Python3 on platforms where it is supported.

  • Using twine for upload to PyPI now as recommended on their site.

  • Running pylint on Windows became practical again.

  • Added RPM packages for Fedora 26 and 27, these used to fail due to packaging issues.

  • Added RPM packages for openSUSE Leap 42.2, 42.3 and 15.0 which were simply missing.

  • Added RPM packages for SLE 15.

  • Added support for PyLint 1.8 and its new warnings.

  • The RPM packages no longer contain nuitka-run3, it will be replaced by the new nuitka3-run which is in all packages.

  • The runners used for installation are now easy install created, but patched to avoid overhead at run time.

  • Added repository for Ubuntu Artful (17.10) for download, removed support for Ubuntu Yakkety, Vivid and Zesty (no more supported by them).

  • Removed support for Debian Wheezy and Ubuntu Precise (they are too old for modern packaging used).

  • There is now a issue template for GitHub when used.


  • Windows: Standalone tests were referencing an old path to depends.exe that wasn’t populated on new installs.

  • Refinements for CPython test suites to become more stable in results. Some tests occasionally fail to clean up, or might do nondeterministic outputs, or are not relevant at all.

  • The tests don’t use the runners, but more often do -m nuitka to become executable without having to find the proper runner. This improves usage during the RPM builds and generally.

  • Travis: Do not test development versions of CPython, even for stable release, they break too often.


This release consolidates a lot of what we already had, adding hopeful stuff for distutils integration. This will need tests and documentation though, but should make Nuitka really easy to use. A few features are still missing to make it generally reliable in that mode, but they are going to come.

Also the locals dictionary work is kind of incomplete without a proper generic tracing of not only local variables, but also dictionary keys. With that work in place, a lot of improvements will happen.