05 February 2024

Nuitka Release 2.0

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

This release had focus on new features and new optimization. There is a really large amount of compatibility with things newly added, but also massive amounts of new features, and esp. for macOS and Windows, lot of platform specified new abilities and corrections.

Bug Fixes

  • Fix, workaround for private functions as Qt slots not having names mangled. Fixed in 1.9.1 already.

  • Fix, when using Nuitka with pdm it was not detected as using pip packages. Fixed in 1.9.1 already.

  • Fix, for pydantic our lazy loader parser didn’t handle all cases properly yet. Fixed in 1.9.1 already.

  • Standalone: Added data files for pyocd package. Fixed in 1.9.1 already.

  • Standalone: Added DLL for cmsis_pack_manager package. Fixed in 1.9.1 already.

  • Standalone: Fix, the specs expanded at run time in some causes could contain random characters. Fixed in 1.9.2 already.

  • Fix, {"a":b, ...}.get("b") could crash at runtime. Fixed in 1.9.2 already.

  • Standalone: Added data files for pyproj package. Fixed in 1.9.2 already.

  • Standalone: Added more metadata requirements for transformers package. Fixed in 1.9.2 already.

  • Plugins: Fix, could crash when including packages from the command line, if they had yaml configuration that requires checking the using module, e.g. anti-bloat work. Fixed in 1.9.3 already.

  • Standalone: Added support for delphifmx package. Fixed in 1.9.4 already.

  • Android: Fix, cannot exclude libz on that platform, it’s not a full Linux OS. Fixed in 1.9.3 already.

  • Standalone: Add needed DLLs for bitsandbytes package. Fixed in 1.9.3 already.

  • Windows: Fix, newer joblib was not working anymore. Fixed in 1.9.3 already.

  • Windows: Fix, could crash when working with junctions that switch drives. Fixed in 1.9.3 already.

  • Fix, was crashing with poetry installed environments. Fixed in 1.9.3 already.

  • Standalone: Added support for newer chromadb package. Fixed in 1.9.3 already.

  • Fix, could crash in report creation on modules excluded that were asked via command line for inclusion. Fixed in 1.9.3 already.

  • Anti-Bloat: Fix for newer streamlit, it was causing SyntaxError for the compilation. Fixed in 1.9.4 already.

  • Arch: Added support for their OS release file location too. Fixed in 1.9.4 already.

  • Windows: Fix, MinGW64 doesn’t accept chinese module names a C source files. Use short paths for these instead. Fixed in 1.9.4 already.

  • Standalone: Added missing DLL for libusb_package package. Fixed in 1.9.4 already.

  • Fix, properly skip directories with non-module top level names when trying to find top level packages of distributions. Fixed in 1.9.4 already.

  • Fix, avoid memory leak bug in triggered by rich package. Fixed in 1.9.4 already.

  • Python3.11+: Fix, didn’t detect non-keywords on star dict calls in some cases. Fixed in 1.9.4 already.

  • Fix, avoid crashes due to unrecognized installers on macOS and Windows, some packages that are built via legacy fallbacks of certain pip versions do not leave any indication of their origin at all. Fixed in 1.9.4 already.

  • Windows: Fix, need to indicate that the program is long path aware or else it cannot work with the paths. Fixed in 1.9.4 already.

  • Debian: The extern namespace might not exist in the pkg_resources module, make the code work with versions that remove it and use the proper external package names then. Fixed in 1.9.6 already.

  • Compatibility: Fix, need to also have .exists method in our files reader objects. Fixed in 1.9.5 already.

  • macOS: Fix, PyQt5 standalone can fail due to libqpdf too.

  • Compatibility: Make dill-compat plugin support module mode too, previously this only worked for executables only. Fixed in 1.9.6 already.

  • Standalone: Added data file for curl_cffi package. Fixed in 1.9.6 already.

  • Windows: Fix warnings given by MinGW64 in debug mode for onefile compilation. Fixed in 1.9.6 already.

  • Python2: The handling of DLL permission changes was not robust against using unicode filenames. Fixed in 1.9.7 already.

  • Python2: Fix, could crash on Debian packages when detecting their installer. Fixed in 1.9.7 already.

  • Standalone: Added required data file for astor package. Fixed in 1.9.7 already.

  • Reports: Fix, in case of build crashes during optimization, the bug report creation could be crashing because the module is not in the list of done modules yet. Fixed in 1.9.7 already.

  • Python2: Fix, unittest.mock was not yet available, code attempting to use it was crashing the compilation. Fixed in 1.9.7 already.

  • Accelerated: Fix, tensorflow configuration removing site usage needs to apply only to standalone mode. Fixed in 1.9.7 already.

  • Plugins: Fix, the get_dist_name Nuitka package configuration function could crash in some rare configurations. Fixed in 1.9.7 already.

  • Standalone: Added necessary data file for pygame package. Added in 1.9.7 already.

  • Standalone: Fix, was not properly handling standard library overloading module names for decisions. Inclusion and compilation mode were made as if the module was part of the standard library, rather than user code. This is now properly checking if it’s also an actual standard library module.

  • Plugins: Fix, crashing on missing absence message with no UPX binary was found.

  • Windows: Fix, couldn’t load extension modules from UNC paths, so standalone distributions failed to launch from network drives. This now works again and was a regression from adding support for symlinks on Windows.

  • Standalone: Added support for non-legacy pillow in imageio package.

  • Standalone: Added required easyOCR data file.

  • Nuitka-Python: Fix, do not demote to non-LTO for “too many” modules there in the default auto mode, it doesn’t work without it.

  • Fix, python setup.py install could fail. Apparently it tries to lookup Nuitka during installation, which then could fail, due to hacks we due to make sure wheels are platform dependent. That hack is of course not really needed for install, since no collision is going to happen there.

  • macOS: Fix, the standard matplotlib plugin that uses native UI was not included yet, and it was also not working due to bindings requiring uncompiled functions, which is now worked around.

  • Compatibility: Add back PySide6 workaround for overloading names like update with slots.

  • Standalone: Added geopandas data files.

  • Python2: Fix, code objects must be made from str exactly, unicode however was used in some configurations after recent improvements to the run time path handling.

  • Standalone: Added missing data files for boto, the predecessor of boto3 as well.

  • Standalone: Added missing DLL for tensorflow factorization module.

  • Compatibility: Fix, PySide2 and PySide6 signal disconnection without arguments were not working yet.

  • Standalone: Added support for toga.

  • Scons: Fix, need to Avoid picking up clang from PATH on Windows with --clang provided, as only our winlibs version is really working.

  • Fix, version of setuptools when included (which we try to avoid very much) was None which breaks some users of it, now it’s the correct version so checks of e.g. setuptools_scm can succeed.

  • Fix, icon options for platforms were conflated, so what should be windows only icon could get used on other platforms as well.

  • Fix, could not create compiled methods from compiled methods. Also now errors out for invalid types given properly.

New Features

  • Plugins: Added support for module decisions, these are parameters provided by the user which can be used to influence the Nuitka per package configuration with a new get_parameter function. We are using these to control important choices in the user, sometimes warning it to make that decision, if the default can be considered problematic.

  • Plugins: Added support for variables in Nuitka package configurations. We can now query at compile time, values from installed packages and use them, e.g. to know what backend is to be used.

  • Standalone: Added module decision to disable Torch JIT. This is generally the right idea, but the decision is still asked for since some packages and programs want to do Torch Tracing, and that is then disabled as well. This makes a bunch of transformers programs work.

  • Standalone: Added module decision to disable Numba JIT. This makes numba work in some cases, but not all. Some packages go very deep with JIT integration, but simpler uses will now compile.

  • New option --include-onefile-external-data allows you to specify file patterns that you included by other data files others, but to put those files not inside, but on the outside of the onefile binary. This makes it easier to create deployments fully within Nuitka project configuration, and to change your mind back and forth without adding/removing the data file option.

  • macOS: Added new value auto for detecting signing identity, if only one is available in the system.

  • macOS: Added support for --copyright and --trademark information to be in app bundles as well, this was previously Windows only.

  • Windows: Added support for using junctions in the Python environment, these are used e.g. when installing via scoop. Added in 1.9.2 already.

  • Added option --cf-protection to select the control flow protection mode for the GCC compiler and deviate from default values of some environments to less strict values.

  • Reports: Added output filename to report, mainly intended for automatically locating the compilation result independent of options used.

  • Plugins: Now provides a checksum for yaml files, but not yet verifies them at runtime, to ask the user to run the checker tool to update it when they make modifications.

  • Windows: Detect when we create too large compiled executables. There is a limit of 2GB that you might e.g. violate by attempting to embed very large files. This doesn’t cover onefile yet.

  • Watch: The tool can now create PRs with the changes in Nuitka-Watch for merging, this is for using it in the CI.

  • Watch: Scanning for Python versions now requires pipenv to be installed in them to be found.

  • Watch: Added ability to create branch and PR from watch run results.

  • Plugins: Added overridden-environment-variables feature to package configuration. These are environment variable changes that only last during the import of that module and are undone later.

  • Plugins: Added force-environment-variables feature to package configuration. These are environment variable changes done on module import that are not undone.

  • Nuitka-Action: Nuitka options that can be given multiple times, cannot be specified multiple times in your workflow. As a workaround, Nuitka now allows in Actions, to use new lines as separator. This is best done with this kind of quoting a multiline string.

    include-data-dir: |
  • The Nuitka package configuration no-auto-follow now applies recursively, i.e. that a top level package can have it, and not every sub-package that uses a package but should not be automatically followed, does have to say this. With this e.g. networkx configuration became simpler, and yet covered automatically older versions as well, and future changes too.

  • Windows: Added support for compiling in case sensitive folders. When this option is enabled, using os.path.normcase can make filenames not found, so with a few cleanups, for lazy code that wasn’t really using the APIs designed for comparisons and filename suffix testing, this works now better.

  • The __compiled__ value has a new attribute containing_dir that allows to find where a module, accelerate executable, a standalone dist folder, a macOS app bundle, or the onefile binary lives in a consistent fashion. This allows esp. better use than sys.argv[0] which points deep into the .app bundle, and can be used cross platform.


  • Scalability: Avoid variables that are not shared to be treated as if they were, marking their type shape as tshape_unknown in the first micro pass. These micro passes are not visible, but basically constitute a full visit of the module tree over and over, until no more optimization is changing it. This can lead to quicker resolution, as that unknown type shape effectively disallowed all optimization for variables and reduce the number of necessary micro passes by one.

  • Escaped variables did provide a type shape tshape_unknown and while a lot of optimization looks for value knowledge, and gets by the escaped nature of the value, sometimes, this was seriously inhibiting some of the type based optimization.

  • Loop type shape analysis now succeeds in detecting the types for this code example, which is sort of a break-through for future performance enhancements in generated code.

    # Initial the value of "i" is "NUITKA_NINT_UNASSIGNED" in its
    # indicator part. The C compiler will remove that assignment
    # as it's only checked in the assignment coming up.
    i = 0
    # Assignment from a constant, produces a value where both the C
    # and the object value are value. This is indicated by a value
    # of "NUITKA_NINT_BOTH_VALID". The code generation will assign
    # both the object member from a prepared value, and the clong
    # member to 0.
    # For the conditional check, "NUITKA_NINT_CLONG_VALID" will
    # always be set, and therefore function will resort to comparing
    # that clong member against 9 simply, that will always be very
    # fast. Depending on how well the C compiler can tell if an overflow
    # can even occur, such that an object might get created, it can even
    # optimize that statically. In this case it probably could, but we
    # do not rely on that to be fast.
       # Here, we might change the type of the object. In Python2,
       # this can change from ``int`` to ``long``, and our type
       # analysis tells us that. We can consider another thing,
       # not "NINT", but "NINTLONG" or so, to special case that
       # code. We ignore Python2 here, but multiple possible types
       # will be an issue, e.g. list or tuple, float or complex.
       # So this calls a function, that returns a value of type
       # "NINT" (actually it will become an in-place operation
       # but lets ignore that too).
       # That function is "BINARY_OPERATION_ADD_NINT_NINT_CLONG"(i, 1)
       # and it is going to check if the CLONG is valid, add the one,
       # and set to result to a new int. It will reset the
       # "NUITKA_NINT_OBJECT_VALID" flag, since the object will not be
       # bothered to create.
       i = i + 1
    # Since "NUITKA_INT_OBJECT_VALID" not given, need to create the
    # PyObject and return it.
    return i
  • Python3.11+: Use tomllib from standard library for our distutils integration into pyproject based builds.

  • Avoid late specialization for None returns in generators and do it during tree building already, to remove noise.

  • Added successful detection of static libpython for self compiled Python Linux and macOS. This makes it work with pyenv as well.

  • Standalone: Avoid including .pyx files when scanning for data files, these are code files too, in this case source files that are definitely unused most of the time.

  • macOS: Make static libpython default with CPython for more compact standalone distribution and faster binaries.

  • Remove non-existent entries from sys.path, avoiding many file system lookups during import scans.

  • Anti-Bloat: Avoid using triton in torch package in more cases. Added in 1.9.2 already.

  • Anti-Bloat: Avoid using pytest in knetworkx package in more cases. Added in 1.9.2 already.

  • Anti-Bloat: Avoid using IPython in distributed package. Added in 1.9.3 already.

  • Anti-Bloat: Avoid using dask in skimage. Added in 1.9.3 already.

  • Anti-Bloat: Avoid using triton in the bitsandbytes package. Added in 1.9.3 already.

  • Anti-Bloat: Avoid IPython in tf_keras package as well. Added in 1.9.6 already.

  • Anti-Bloat: Avoid unittest in mock.mock module. Added in 1.9.7 already.

  • Avoid importing setuptools_scm during compilation when using the tqdm inline copy, this also avoids a warning on Ubuntu. Added in 1.9.7 already.

  • Anti-Bloat: Avoid doctest in skimage in their tifffile inline copy as well. Added in 1.9.7 already.

  • Anti-Bloat: Avoid h5py.tests with older h5py as well. Added in 1.9.7 already.

  • Anti-Bloat: Using distributed.utils_test is also considered using pytest.

  • Anti-Bloat: Avoid IPython in the pip package.

  • Anti-Bloat: Avoid site module for older tensorflow versions too.

  • Anti-Bloat: Avoid more unittest usages in tensorflow packages.

  • Anti-Bloat: Avoid nose in skimage package.

  • Anti-Bloat: Avoid nose in networkx package.

  • Anti-Bloat: Avoid nose in pywt package.


  • UI: Change template paths over from %VAR% to {VAR}.

    The old spec values are migrated transparently and continue to work, but get a warning when used.

    The new code detects unknown variable names and more formatting issues than before.

    Using only the {PID} value for process ID, is now making it temporary value for onefile, that was previously a bug.

    The main benefit and reason of doing this, is that Windows CMD.EXE does expand those values before Nuitka sees them as even with quoting %TEMP% is the current one on the building machine, a recipe for disaster. As some people still use that, and e.g. os.system or subprocess with shell=True will use it too, this is just not sustainable for a good user experience.

    As a result, compile time and run time variables now clash, there is e.g. {VERSION} (program version information given) and {Version} (Nuitka version), and we should clean that up too.

  • Project: Added Code of Conduct. Adapted from the one used in the Linux kernel.

  • UI: Warnings given by Nuitka used to be in red color, changed those to be yellow for consistency.

  • User Manual: Added pointer for Nuitka-Action Nuitka-Action for users interested in using Nuitka in GitHub workflows.

  • Added .gitignore to build folder that just causes these folders to be ignored by git.

  • User Manual: Added information on how to debug fork bombs from created binaries.

  • Debugging: The output of --experimental=--report-refcounts that we use to show leaks of compiled time objects at program exit, now counts and reports on functions, generator objects and compiled cells as well.

  • Quality: Warnings from yamllint not disabled are errors. These were only output, but didn’t cause the autoformat to error exit yet.

  • UI: Enhanced formatting of info traces, drop the :INFO part that shouts, and reserve that for errors and warnings. Also format info messages to make sure they fit into the line.

  • UI: Changed --show-source-changes to accept module pattern to make it easier to only see the ones currently being worked on. To get the old behavior of showing everything, use * as a pattern.

  • UI: Allow using ~ in data files source path for command line options and expand it properly.

  • Quality: Enhanced schema for our package configuration yaml files to detect suffixes with leading dots, that is not wanted. These now fail checks, but we also tolerate them now.

  • Quality: Check module names used in the package configuration yaml files for validity, this catches e.g. trailing dots.

  • Quality: Make sure to really prefer clang-format from Visual Code and MSVC for formatting C code, otherwise a system installed one could be used that gives slightly different outputs.

  • Scons: Allow disabling to enforce no warnings for C compilation

    Currently only for gcc, where we need it until loop tracing is better, we can now use --experimental=allow-c-warnings options to make --debug work for some known currently unavoidable warnings.

  • macOS: Make --macos-create-app-bundle imply standalone mode, it’s not working or useful for accelerated mode anyway.

  • Standalone: Added support for using self-compiled Python versions that are not installed on Linux and macOS. This avoids having to do make install and can ease debugging with changes made in Python core itself. Added in 1.9.6 already.

  • Release: Added ability to simple re-date hotfixes. Previously the version bump commit needed to be dropped, now a fixup commit is easy to generate.

  • Release: Man pages are no longer built during package builds, but are available statically in the git, which should make it easier.

  • Release: Disable verbose output in package installation of Nuitka, it never was any use, and just makes things hard to read.

  • UI: Check user yaml file present immediately. Otherwise it was crashing when parsing yaml files first time with less comprehensible exceptions. Added in 1.9.7 already.

  • Quality: Updated to latest rstfmt, black and isort versions.

  • Debian: Remove references to PDF documentation that no longer exists.

  • Quality: Do not crash when collecting modified files due to deleted files.

  • UI: Detect the Alpine flavor of Python as well.

  • UI: Detect manylinux Pythons as a Python flavors as well.

  • UI: Detect self compiled uninstalled Python as a dedicated flavor.


  • For the Nuitka-Action part of the available options is now generated from Nuitka option definitions itself, adding some previously missing options as a result. As a result, adding --include-onefile-external-data was automatic this time.

  • The warnings for onefile only options without onefile mode provided have been moved to common code, and in some cases were having wrong texts corrected.

  • Use enum definitions in the Nuitka package configuration schema rather than manual oneOf types.

  • The User Manual was proof read and had a bunch of wordings improved.

  • Cleanup, avoid “unused but set variable” warning from the C compiler for hard some forms of hard imports.

  • Prefer os.getenv over os.environ.get for readability.

  • Changed parts of the C codes that clang-format had a hard time with to something more normal.


  • When locating the standalone binary created, use a compilation report and resolve the path specified there. This allows macOS app bundles to be used in these tests as well.

  • Made the PyQt tests executable on macOS too adding necessary options.

  • Added reference test case for unpacking into a list, this was not covered but under suspect of reference leaking which turns out to be wrong.

  • Much enhanced usage of virtualenv in the distutils test cases. We make more sure to delete them even in case of issues. We disable warnings during Nuitka package installation. The code to execute a case was factored out and became more clear. We now handle errors in execution with stating what case actually failed, this was a bit hard to tell previously. Also do not install Nuitka when a pyproject case is used, since the build tool installs Nuitka itself.


This release deserves the 2.0 marker, as it is ground breaking in many ways. The loop type analysis stands out on the optimization front. This will open an avenue for much optimized code at least for some benchmark examples this summer.

The new features for package configuration, demonstrate abilities to avoid plugins for Nuitka, where those previously would have been used. The new variables and parameters made it unnecessary to have them, and still add compile time variable use and user decisions and information, without them.

The scope of supported Python configurations got expanded a bit, and the the usual slew of anti-bloat work and new packages supported, makes Nuitka an ever more round package.

The improved user dialog with less noisy messages and slightly better coloring, continues a trend, where Nuitka becomes more and more easy to use.