Getting started

cx_Freeze is a volunteer maintained open source project and we welcome contributions of all forms. The sections below will help you get started with development, testing, and documentation. We’re pleased that you are interested in working on cx_Freeze. This document is meant to get you setup to work on cx_Freeze and to act as a guide and reference to the development setup. If you face any issues during this process, please open an issue about it on the issue tracker.


The source code can be found on Github.

You can use git to clone the repository:

git clone
cd cx_Freeze
make install

If you don’t have make installed, run:

python -m pip install --upgrade pip
pip install -e .[dev,doc]
pre-commit install --install-hooks --overwrite -t pre-commit


  1. It is recommended to use a virtual environment.

  2. Please check the requirements for python on your system (see Installation).

Building redistributable binary wheels

When python -m build or pip wheel is used to build a cx_Freeze wheel, that wheel will rely on external shared libraries. Such wheels therefore will only run on the system on which they are built. See Building and installing or uploading artifacts for more context on that.

A wheel like that is therefore an intermediate stage to producing a binary that can be distributed. That final binary may be a wheel - in that case, run auditwheel (Linux) or delocate (macOS) to vendor the required shared libraries into the wheel.

To reach this, cx_Freeze’s binary wheels is built using cibuildwheel.

For instance, in a Linux environment, Python 3.10, to build locally, run:

pip install --upgrade cibuildwheel
CIBW_BUILD=cp310-manylinux_x86_64 cibuildwheel --platform linux


  1. Please read Run cibuildwheel locally.

  2. To run a Linux build on your development machine, Docker or Podman should be installed. To use podman, set CIBW_CONTAINER_ENGINE.

Building documentation

cx_Freeze’s documentation is built using Sphinx. The documentation is written in reStructuredText. To build it locally, run:

make html

The built documentation can be found in the build/doc/html folder and may be viewed by opening index.html within that folder.

make htmltest


If you are installing a pre-release or from sources, install the requirements using the conda-forge channel:

py-lief (Windows)
patchelf (Linux)
# declare SDKROOT or CONDA_BUILD_SYSROOT (for python 3.9+ in macOS)
# for example, in Github Actions CI, macOS:
export SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk

An example for Linux:

conda create -n cx39conda -c conda-forge python=3.9 -y
conda activate cx39conda
conda install -c conda-forge c-compiler patchelf -y
pip install --upgrade --no-binary=cx_Freeze --pre cx_Freeze -v


Submitting pull requests

Submit pull requests against the main branch, providing a good description of what you’re doing and why. You must have legal permission to distribute any code you contribute to cx_Freeze and it must be available under the PSF License. Any pull request must consider and work on the supported platforms.

Pull Requests should be small to facilitate review. Keep them self-contained, and limited in scope. Studies have shown that review quality falls off as patch size grows. Sometimes this will result in many small PRs to land a single large feature. In particular, pull requests must not be treated as “feature branches”, with ongoing development work happening within the PR. Instead, the feature should be broken up into smaller, independent parts which can be reviewed and merged individually.

Additionally, avoid including “cosmetic” changes to code that is unrelated to your change, as these make reviewing the PR more difficult. Examples include re-flowing text in comments or documentation, or addition or removal of blank lines or whitespace within lines. Such changes can be made separately, as a “formatting cleanup” PR, if needed.