Release notes

6.x releases

  1. Highlights of Version 6.2 and 6.3:
    • Initial support for metadata to use by pkg_resources and importlib.metadata
    • Namespace packages are automatically detected
    • Enhanced support for Python 3.8
    • Better support for MSYS2
    • More integrated to setuptools
    • Fixed long-awaited bugs and recent bugs
    • Fixed issues with multiprocessing (see Windows section of 6.2)

Version 6.3 (October 2020)

  1. Improvements:
  2. New or improved hooks for:
  3. Linux:
    • Improve copy dependent files relative to source module file (linux) (PR #704)
  4. Windows:
    • Check if upgrade-code is valid and document the valid format (PR #711, Issue #585)
    • Improve Windows GUID documentation (PR #749)
    • Added option to bdist_msi to specify information for msi summary information stream (PR #760)
  5. macOS:
  6. Samples:
    • Add pyside2 sample (PR #664)
    • A sample for testing PyQt5 included in zip package (PR #717)
    • Add pandas sample (PR #709)
    • Added sample code to show the use of ConstantsModule / BUILD_CONSTANTS (PR #729)
  7. Bugfixes:
    • Ensure the copy of default python libraries in all platforms (PR #706, :issue:`701)
    • Remove warning ‘Distutils was imported before Setuptools’ (PR #694, Issue #693)
    • Fix the use of compress and desambiguate the use of stat (PR #738)
    • Small fix to handle a build constant that includes a “=” symbol. (PR #728)
    • Fix issue when module.file is None (PR #707)
    • Fix detect namespaces in py35 (PR #700)
    • Set python initialization flags prior to Py_SetPath call to avoid warnings (PR #751)

Version 6.2 (July 2020)

  1. New or improved hooks for:
  2. Linux:
  3. Windows:
  4. macOS:
    • Fixing modification of PATH for single user install (PR #614, Issue #613)
    • Make needed dirs when using include_resources (PR #633)
    • Check for Mach-O using byte strings to allow case of non unicode chars (PR #635)
    • Copy references from /usr/local (PR #648)
  5. Documentation
  6. Misc
    • Fixed bug in cxfreeze script introduced in 6.1 (Issue #560).
    • Remove old packages/modules names, do not report as missing (PR #605)
    • Better support for MSYS2 and Anaconda3 (PR #642)
    • Support python 3.5.2 and up (PR #606)
    • Support metadata to use by pkg_resources (PR #608)
    • New commom function rebuild_code_object to be reusable (PR #629)
    • Fix optimize option in python 3.8 (PR #641)
    • Add –include-files option to cxfreeze script (PR #647)
    • Replace the value of __package__ directly in the code (PR #651)
    • Eliminate exclusion of dbm module since it is in Python 3 (PR #662, Issue #660)
    • Detect namespace packages (PR #669, PR #668)
    • Installing from source requires setuptools (PR #687)
    • Remove PyUnicode_FromUnicode (PR #673)

Version 6.1 (January 2020)

  1. Added support for Python 3.8 (PR #545, PR #556).
  2. Added support for python develop (PR #502).
  3. Use console_scripts in entry_points so that the commands cxfreeze and cxfreeze-quickstart run on Windows without the need for running a postinstall script (PR #511).
  4. Added support for switching from per-user to per-machine installations on Windows (PR #507).
  5. Fix installation if AlwaysInstallElevated policy is set on Windows (PR #533).
  6. Updated default dependencies for Python 3 on Windows (PR #505).
  7. Removed unused code (PR #549).
  8. The default dependencies are now always copied into the lib folder instead of into the directory where the executable resides on Linux (PR #518).
  9. Dependent files are now copied to the same relative directory as their location in the source on Linux (PR #494).
  10. Added tests for commonly used packages like cryptography, pillow, sqlite, pytz, ctypes and distutils (PR #508, PR #537, PR #546, PR #555, PR #557).
  11. Fix regression with DLL dependencies introduced in 6.0 by PR #492 due to case differences (PR #512).
  12. Fix regression with dependent files introduced in 6.0 by PR #297 for platforms other than macOS (PR #516).
  13. The version of cx_Freeze is now defined in one place (PR #552).
  14. Eliminate exclusion of gestalt module on platforms other than macOS since it exists outside of macOS.
  15. Improved hooks for sqlite3 (PR #509), cryptography, and tkinter (PR #559).
  16. Added hook for pytz (PR #554).
  17. Improved hook infrastructure, permitting hooks to add constants that can be examined at runtime, determine whether a module is going to be stored in the file system and include files in the zip file.
  18. Improved documentation (PR #510).

Version 6.0 (August 2019)

  1. Corrected support for Python 3.7 (PR #395).
  2. Use importlib and other Python 3 improvements (PR #484, PR #485, PR #486, PR #490).
  3. Fixed issue with @rpath causing file copy errors on macOS (PR #307).
  4. Replaced file() with open() and use context manager to ensure the file handle is closed and deleted (PR #348).
  5. Corrected invalid version handling in bdist_msi (PR #349, Issue #340).
  6. Corrected hook for clr module (PR #397, PR #444).
  7. Corrected documentation for compress option (PR #358).
  8. Ensure that the pythoncom and pywintypes DLLs are found in the lib directory and not in the base directory (Issue #332).
  9. Always copy dependent files to root directory on macOS (PR #365).
  10. Skip self referencing archive on macOS (PR #364, Issue #304).
  11. Include doc directory in source distribution (PR #394, Issue #376).
  12. Force msilib module to be reloaded in order to allow for the generation of multiple MSI packages in a single session (PR #419).
  13. Added hook for PyQt5.QtPrintSupport module (PR #401).
  14. Added ability to include an icon on the add/remove program window that pops up during installation (PR #387).
  15. Prevent spurious errors from being printed during building on macOS by checking to see that a file is a Mach-O binary before adding it to the list of files it is checking the reference of (PR #342, Issue #268).
  16. Avoid otool bug on macOS Yosemite (PR #297, Issue #292).
  17. Added ability to specify environment variables that should be created when an MSI package is installed (PR #266).
  18. Added support for including resources in an app bundle for macOS (PR #423).
  19. Added absolute reference path option for macOS packages (PR #424).
  20. Added CFBundle identifier for macOS packages (PR #427, Issue #426).
  21. Added hook for copying SSL DLLs for Python 3.7+ on Windows (PR #470).
  22. Added -municode flag when building on Windows with mingw32 (PR #468).
  23. Added hook for pycparser (PR #446).
  24. Fixed hook for zmq so it doesn’t fail when there is no bundled libzmq library in the installed pyzmq package (PR #442).
  25. Print error when fetching dependent files fails (PR #435).
  26. Make executable writable before adding the icon (PR #430, Issue #368).
  27. Dropped support for RPM and MSI packages for cx_Freeze itself since these are no longer supported by PyPI.
  28. Fix building console app with mingw32 (PR #475).
  29. Force inclusion of the unicodedata module which is used by the socket module, and possibly others (PR #476).
  30. Added hook for asyncio package (PR #477).
  31. Added hook for idna package (PR #478).
  32. Added hook for pkg_resources package (PR #481).
  33. Added hook for gevent (PR #495).
  34. Force .exe extension to be included on Windows, so that the same setup code can be used on both Linux and Windows (PR #489).
  35. Added hook for Pillow (PR #491).
  36. Improved hook for tkinter (PR #493).
  37. Avoid attempting to check for dependent files on Windows when the file is not an executable or DLL (PR #492).
  38. Ensure that only executable files are checked for dependencies in order to avoid spurious errors when checking for dependent files.
  39. Improved hook for matplotlib.

Version 6.0b1 (November 2017)

  1. Dropped support for Python 2.x. Use cx_Freeze 5 for Python 2.x support.
  2. Instead of depending on the built-in functionality of searching for a zip file that looks like (which is disabled on some platforms like Ubuntu), set the Python path to include a subdirectory called “lib” and a zip file “lib/” on all platforms.
  3. Do not create version resource when version is omitted (PR #279).
  4. Ensure the sqlite3 DLL is loaded in the same directory as the module which depends on it (Issue #296).

5.x releases

Version 5.1.1 (December 2017)

  1. Correct code used to identify the directory in which the library and its zip file are located (Issue #324, Issue #325).
  2. Ensure that the pythoncom and pywintypes DLLs are found in the lib directory, not in the base directory (Issue #332).
  3. Copy dependent files to the same directory as the file it depends on, not the root directory; also add a sample for PyQt5 to demonstrate its correct use (Issue #328).

Version 5.1 (November 2017)

  1. Use fixed library location on all platforms; should correct the error “no module named __startup__” (PR #286).
  2. Correct sqlite3 hook for use in Python 2.7 (PR #272).
  3. Correct usage of scipy.lib (PR #281).
  4. Correct handling of __path__ attribute in module (PR #295).
  5. Fix gevent bug #42 (PR #301).
  6. Droppped support for Python 3.4.

Version 5.0.2 (May 2017)

  1. Correct handling of import in child thread (PR #245)
  2. Correct handling of “dis” module with Python 3.5.1 (Issue #225)
  3. Correct handling of “multiprocess.process” module (Issue #230)
  4. Correct attempt to assign variable to an empty list (PR #260)
  5. Improved README (PR #235, PR #236)
  6. Add hook for pythonnet package (PR #251)
  7. Add hook for sqlite3 and improve win32file hook (PR #261)
  8. Add FAQ entry (PR #267)

Version 5.0.1 (January 2017)

  1. Added support for Python 3.6.
  2. Corrected hooks for the pythoncom and pywintypes modules.
  3. Use realpath() to get the absolute path of the executable; this resolves symbolic links and ensures that changing the path before all imports are complete does not result in the executable being unable to find modules.
  4. Correct issue with usage of ‘if __main__ == “__main__”’. (Issue #211)
  5. Correct handling of the zip_include_packages option. (Issue #208)
  6. Correct logic regarding importing of submodules. (Issue #219)

Version 5.0 (November 2016)


This version supports Python 2.7 and above.

  1. Added support for Python 3.5.
  2. Switched from using C compiled frozen modules which embed part of the standard library to using the default named zip file and library file locations. This eliminates the need to recompile cx_Freeze for each new Python version as no parts of the standard library are included in the installation now. This also implies that appending a zip file to the executable is no longer supported since the standard name and location are used.
  3. Removed unnecessary options and parameters from cx_Freeze. (PR #60, PR #67)
  4. Added support for Win32Service base with Python 3.x. (PR #49)
  5. Add __version__ as an alias to version. (PR #65)
  6. Updated hooks for PyQt, h5py. (PR #68, PR #64, PR #70)
  7. Set copyDependentFiles = True for include files. (PR #66)
  8. Reallow including modules with non-identifier names. (PR #79)
  9. Fix missing space in Windows installer. (PR #81)
  10. Use pattern “not in string” isntead of “string.find(pattern)” (PR #76)
  11. Fix –add-to-path writing to the per-user instead of system environment (PR #86)
  12. Fix documentation (PR #77, PR #78)
  13. Do not import excluded submodules. (PR #89)
  14. Correct distribution files for bdist_msi (PR #95)
  15. Allow proper handling of Unicode command line parameters under Windows (PR #87)
  16. Add pyzmq hook (PR #63)
  17. Add copyright and trademarks to version information (PR #94)
  18. Fix compilation on Ubuntu (Issue #32)
  19. Set defaults in class directly, rather than as defaults in the function signature. (Issue #185)
  20. Correct relative import of builtin module (cx_Freeze was incorrectly considering it an extension found within a package). (Issue #127)
  21. Ensure that included files are added relative to the executable, not to the location of the zip file. (Issue #183)
  22. Prevent infinite loop while using cx_Freeze installed in a prefix. (Issue #204)
  23. Added support for storing packages in the file system instead of in the zip file. There are a number of packages that assume that they are found in the file system and if found in a zip file instead produce strange errors. The default is now to store packages in the file system but a method is available to place packages in the zip file if they are known to behave properly when placed there. (Issue #73)
  24. Added support for untranslatable characters on Windows in the path where a frozen executable is located. (Issue #29)
  25. Use volume label to name the DMG file (Issue #97)
  26. Significantly simplified startup code.
  27. Added logging statements for improved debugging.
  28. Updated samples to handle recent updates to packages.
  29. Avoid infinite loop for deferred imports which are cycles of one another.

Version 4.3.4 (December 2014)


This version supports Python 2.6 and above.

  1. Rebuilt for Python 3.4.2. Dropped support for Python versions less than 2.6.
  2. Correct stale comment. (PR #50)
  3. Fix processing path specs from config when targets are not explicit. (PR #53)
  4. Tweaks to improve compiling with MSVC 10 (2010) on Windows. (PR #54)
  5. Added support for using the –deep and –resource-rules options when code signing through cx_Freeze on OS X. (PR #55)
  6. Catch error if GetDependentFiles() is called on a non-library (PR #56)
  7. Added FAQ entry on single file executables (PR #58)
  8. Only look one level deep for implicit relative imports (PR #59)
  9. Removed statement that was filtering out the ntpath module. (PR #74)

Version 4.3.3 (May 2014)


This version supports Python 2.4 and above.

  1. Added support for release version of 3.4 (PR #47, PR #48)
  2. Added support for code signing in bdist_mac (PR #40)
  3. Added custom Info.plist and Framework suport to bdist_mac (PR #33)
  4. Added support for resolving dependencies on OS X where paths are relative (PR #35)
  5. Added hook for QtWebKit module (PR #36)
  6. Added support for finding packages inside zip files (PR #38)
  7. Ensure that syntax errors in code do not prevent freezing from taking place but simply ignore those modules (PR #44, PR #45)
  8. Init scripts now use code that works in both Python 2 and 3 (PR #42)
  9. Simplify service sample (PR #41)
  10. Fix documentation for bdist_dmg (PR #34)
  11. All options that accept multiple values are split on commas as documented (PR #39)
  12. Truncated names in Python tracebacks (Issue #52)
  13. install_name_tool doesn’t set relative paths for files added using include_files option (Issue #31)

Version 4.3.2 (October 2013)

  1. Added support for Python 3.4.
  2. Added hooks for PyQt4, PyQt5 and PySide to handle their plugins.
  3. Added support for creating a shortcut/alias to the Applications directory within distributed DMG files for OS X.
  4. Improve missing modules output.
  5. Avoid polluting the extension module namespace when using the bootstrap module to load the extension.
  6. Added support for using setuptools and pip if such tools are available.
  7. Added first tests; nose and mock are required to run them.
  8. Remove –bundle-iconfile in favor of –iconfile as a more generic method of including the icon for bdist_mac.
  9. Documentation improved and FAQ added.
  10. Converted samples to follow PEP 8.
  11. cxfreeze-quickstart failed if the default base was not used
  12. scripts frozen with Python 3 fail with an ImportError trying to import the re module
  13. fix bug where after a first attempt to find a module failed, the second attempt would erroneously succeed
  14. stop attempting to load a module by a name that is not a valid Python identifier

Version 4.3.1 (November 2012)


This version supports Python 2.4 and above. If you need Python 2.3 support, please use cx_Freeze 4.2.3.

  1. Added support for the final release of Python 3.3.
  2. Added support for copying the MSVC runtime DLLs and manifest if desired by using the –include-msvcr switch. Thanks to Almar Klein for the initial patch.
  3. Clarified the documentation on the –replace-paths option. Thanks to Thomas Kluyver for the patch.
  4. Producing a Mac distribution failed with a variable reference.
  5. Freezing a script using PyQt on a Mac failed with a type error.
  6. Version number reported was incorrect. (Issue #7)
  7. Correct paths during installation on Windows. (Issue #11)

Version 4.3 (July 2012)


This version supports Python 2.4 and above. If you need Python 2.3 support, please use cx_Freeze 4.2.3.

  1. Added options to build Mac OS X application bundles and DMG packages using bdist_mac and bdist_dmg distutils commands. Written by Rob Reilink.
  2. The documentation is now using Sphinx, and is available on
  3. Added support for Python 3.3 which uses a different compiled file format than earlier versions of Python.
  4. Added support for Windows services which start automatically and which are capable of monitoring changes in sessions such as lock and unlock.
  5. New cxfreeze-quickstart wizard to create a basic file. Initially written by Thomas Kluyver.
  6. Included files under their original name can now be passed to include_files as a tuple with an empty second element. Written by r_haritonov.
  7. File inclusions/exclusions can now be specified using a full path, or a shared library name with a version number suffix.
  8. Messagebox display of certain errors in Windows GUI applications with Python 3.
  9. Running Windows GUI applications in a path containing non-ASCII characters.
  10. Calculate the correct filename for the Python shared library in Python 3.2.
  11. Including a package would not include the packages within that package, only the modules within that package. (Issue #3)

Version 4.2.3 (March 2011)

  1. Added support for Python 3.2.
  2. Added hook for datetime module which implicitly imports the time module.
  3. Fixed hook for tkinter in Python 3.x.
  4. Always include the zlib module since the zipimport module requires it, even when compression is not taking place.
  5. Added sample for a tkinter application.

Version 4.2.2 (December 2010)

  1. Added support for namespace packages which are loaded implicitly upon startup by injection into sys.modules.
  2. Added support for a Zope sample which makes use of namespace packages.
  3. Use the Microsoft compiler on Windows for Python 2.6 and up as some strange behaviors were identified with Python 2.7 when compiled using mingw32.
  4. Eliminate warning about -mwindows when using the Microsoft compiler for building the Win32GUI base executable.
  5. Added support for creating version resources on Windows.
  6. Ensure that modules that are not truly required for bootstrapping are not included in the frozen modules compiled in to the executable; otherwise, some packages and modules (such as the logging package) cannot be found at runtime. This problem only seems to be present in Python 2.7.1 but it is a good improvement for earlier releases of Python as well.
  7. Added support for setting the description for Windows services.
  8. Added hook for using the widget plugins which are part of the PyQt4.uic package.
  9. Added additional hooks to remove spurious errors about missing modules and to force inclusion of implicitly imported modules (twitter module and additional submodules of the PyQt4 package).
  10. Fixed support for installing frozen executables under Python 3.x on Windows.
  11. Removed optional import of setuptools which is not a complete drop-in replacement for distutils and if found, replaces distutils with itself, resulting in some distutils features not being available; for those who require or prefer the use of setuptools, import it in your

Version 4.2.1 (October 2010)

  1. Added support for specifying bin_path_includes and bin_path_excludes in setup scripts.
  2. Added support for compiling Windows services with the Microsoft compiler and building for 64-bit Windows.
  3. When installing Windows services, use the full path for both the executable and the configuration file if specified.
  4. Eliminate duplicate files for each possible version of Python when building MSI packages for Python 2.7.
  5. Fix declaration of namespace packages.
  6. Fix check for cx_Logging import library directory.
  7. Added hooks for the python-Xlib package.
  8. Added hooks to ignore the _scproxy module when not on the Mac platform and the win32gui and pyHook modules on platforms other than Windows.
  9. When copying files, copy the stat() information as well as was done in earlier versions of cx_Freeze.
  10. Added documentation for the shortcutName and shortcutDir parameters for creating an executable.

Version 4.2 (July 2010)

  1. Added support for Python 2.7.
  2. Improved support for Python 3.x.
  3. Improved support for Mac OS X based on feedback from some Mac users.
  4. Improved hooks for the following modules: postgresql, matplotlib, twisted, zope, PyQt4.
  5. Improved packaging of MSI files by enabling support for creating shortcuts for the executables, for specifying the initial target directory and for adding other arbitrary configuration to the MSI.
  6. Added support for namespace packages such as those distributed for zope.
  7. The name of the generated MSI packages now includes the architecture in order to differentiate between 32-bit and 64-bit builds.
  8. Removed use of LINKFORSHARED on the Mac which is not necessary and for Python 2.6 at least causes an error to be raised.
  9. Turn off filename globbing on Windows as requested by Craig McQueen.
  10. Fixed bug that prevented hooks from successfully including files in the build (as is done for the matplotlib sample).
  11. Fixed bug that prevented submodules from being included in the build if the format of the import statement was from . import <name>.
  12. Reverted bug fix for threading shutdown support which has been fixed differently and is no longer required in Python 2.6.5 and up (in fact an error is raised if the threading module is used in a frozen executable and this code is retained).
  13. Fixed bug which resulted in attempts to compile .pyc and .pyo files from the initscripts directory.
  14. Fixed selection of “Program Files” directory on Windows in 64-bit MSI packages built by cx_Freeze.

Version 4.1.2 (January 2010)

  1. Fix bug that caused the util extension to be named improperly.
  2. Fix bug that prevented freezing from taking place if a packaged submodule was missing.
  3. Fix bug that prevented freezing from taking place in Python 3.x if the encoding of the source file wasn’t compatible with the encoding of the terminal performing the freeze.
  4. Fix bug that caused the base modules to be included in the as well as the base executables.

Version 4.1.1 (December 2009)

  1. Added support for Python 3.1.
  2. Added support for 64-bit Windows.
  3. Ensured that setlocale() is called prior to manipulating file names so that names that are not encoded in ASCII can still be used.
  4. Fixed bug that caused the Python shared library to be ignored and the static library to be required or a symbolic link to the shared library created manually.
  5. Added support for renaming attributes upon import and other less frequently used idioms in order to avoid as much as possible spurious errors about modules not being found.
  6. Force inclusion of the traceback module in order to ensure that errors are reported in a reasonable fashion.
  7. Improved support for the execution of ldd on the Solaris platform as suggested by Eric Brunel.
  8. Added sample for the PyQt4 package and improved hooks for that package.
  9. Enhanced hooks further in order to perform hidden imports and avoid errors about missing modules for several additional commonly used packages and modules.
  10. Readded support for the zip include option.
  11. Avoid the error about digest mismatch when installing RPMs by modifying the spec files built with cx_Freeze.
  12. Ensure that manifest.txt is included in the source distribution.

Version 4.1 (July 2009)

  1. Added support for Python 3.x.
  2. Added support for services on Windows.
  3. Added command line option –silent (-s) as requested by Todd Templeton. This option turns off all normal output including the report of the modules that are included.
  4. Added command line option –icon as requested by Tom Brown.
  5. Ensure that Py_Finalize() is called even when exceptions take place so that any finalization (such as __del__ calls) are made prior to the executable terminating.
  6. Ensured that empty directories are created as needed in the target as requested by Clemens Hermann.
  7. The encodings package and any other modules required to bootstrap the Python runtime are now automatically included in the frozen executable.
  8. Ensured that if a target name is specified, that the module name in the zip file is also changed. Thanks to Clemens Hermann for the initial patch.
  9. Enabled support for compiling on 64-bit Windows.
  10. If an import error occurs during the load phase, treat that as a bad module as well. Thanks to Tony Meyer for pointing this out.
  11. As suggested by Todd Templeton, ensured that the include files list is copied, not simply referenced so that further uses of the list do not inadvertently cause side effects.
  12. As suggested by Todd Templeton, zip files are now closed properly in order to avoid potential corruption.
  13. As suggested by Todd Templeton, data files are no longer copied when the copy dependent files flag is cleared.
  14. Enabled better support of scripts that call other scripts such as the ones used by cx_OracleTools and cx_OracleDBATools.
  15. On Solaris, ldd outputs tabs instead of spaces so expand them first before looking for the separator. Thanks to Eric Brunel for reporting this and providing the solution.
  16. On Windows, exclude the Windows directory and the side-by-side installation directory when determining DLLs to copy since these are generally considered part of the system.
  17. On Windows, use %* rather than the separated arguments in the generated batch file in order to avoid problems with the very limited argument processor used by the command processor.
  18. For the Win32GUI base executable, add support for specifying the caption to use when displaying error messages.
  19. For the Win32GUI base executable, add support for calling the excepthook for top level exceptions if one has been specified.
  20. On Windows, ensure that the MSI packages that are built are per-machine by default as otherwise strange things can happen.
  21. Fixed bug in the calling of readlink() that would occasionally result in strange behavior or segmentation faults.
  22. Duplicate warnings about libraries not found by ldd are now suppressed.
  23. Tweaked hooks for a number of modules based on feedback from others or personal experience.

Version 4.0.1 (October 2008)

  1. Added support for Python 2.6. On Windows a manifest file is now required because of the switch to using the new Microsoft C runtime.
  2. Ensure that hooks are run for builtin modules.

Version 4.0 (September 2008)

  1. Added support for copying files to the target directory.
  2. Added support for a hook that runs when a module is missing.
  3. Added support for binary path includes as well as excludes; use sequences rather than dictionaries as a more convenient API; exclude the standard locations for 32-bit and 64-bit libaries in multi-architecture systems.
  4. Added support for searching zip files (egg files) for modules.
  5. Added support for handling system exit exceptions similarly to what Python does itself as requested by Sylvain.
  6. Added code to wait for threads to shut down like the normal Python interpreter does. Thanks to Mariano Disanzo for discovering this discrepancy.
  7. Hooks added or modified based on feedback from many people.
  8. Don’t include the version name in the display name of the MSI.
  9. Use the OS dependent path normalization routines rather than simply use the lowercase value as on Unix case is important; thanks to Artie Eoff for pointing this out.
  10. Include a version attribute in the cx_Freeze package and display it in the output for the –version option to the script.
  11. Include build instructions as requested by Norbert Sebok.
  12. Add support for copying files when modules are included which require data files to operate properly; add support for copying the necessary files for the Tkinter and matplotlib modules.
  13. Handle deferred imports recursively as needed; ensure that from lists do not automatically indicate that they are part of the module or the deferred import processing doesn’t actually work!
  14. Handle the situation where a module imports everything from a package and the __all__ variable has been defined but the package has not actually imported everything in the __all__ variable during initialization.
  15. Modified license text to more closely match the Python Software Foundation license as was intended.
  16. Added sample script for freezing an application using matplotlib.
  17. Renamed freeze to cxfreeze to avoid conflict with another package that uses that executable as requested by Siegfried Gevatter.

Version 4.0b1 (September 2007)

  1. Added support for placing modules in or in a separate zip file for each executable that is produced.
  2. Added support for copying binary dependent files (DLLs and shared libraries)
  3. Added support for including all submodules in a package
  4. Added support for including icons in Windows executables
  5. Added support for constants module which can be used for determining certain build constants at runtime
  6. Added support for relative imports available in Python 2.5 and up
  7. Added support for building Windows installers (Python 2.5 and up) and RPM packages
  8. Added support for distutils configuration scripts
  9. Added support for hooks which can force inclusion or exclusion of modules when certain modules are included
  10. Added documentation and samples
  11. Added for building the cx_Freeze package instead of a script used to build only the frozen bases
  12. FreezePython renamed to a script called freeze in the Python distribution
  13. On Linux and other platforms that support it set LD_RUN_PATH to include the directory in which the executable is located

Older versions

Version 3.0.3 (July 2006)

  1. In Common.c, used MAXPATHLEN defined in the Python OS independent include file rather than the PATH_MAX define which is OS dependent and is not available on IRIX as noted by Andrew Jones.
  2. In the initscript, added lines from initscript that should have been there since the only difference between that script and this one is the automatic re-execution of the executable.
  3. Added an explicit “import encodings” to the initscripts in order to handle Unicode encodings a little better. Thanks to Ralf Schmitt for pointing out the problem and its solution.
  4. Generated a meaningful name for the extension loader script so that it is clear which particular extension module is being loaded when an exception is being raised.
  5. In, use distutils to figure out a few more platform-dependent linker flags as suggested by Ralf Schmitt.

Version 3.0.2 (December 2005)

  1. Add support for compressing the byte code in the zip files that are produced.
  2. Add better support for the win32com package as requested by Barry Scott.
  3. Prevent deletion of target file if it happens to be identical to the source file.
  4. Include additional flags for local modifications to a Python build as suggested by Benjamin Rutt.
  5. Expanded instructions for building cx_Freeze from source based on a suggestion from Gregg Lind.
  6. Fix typo in help string.

Version 3.0.1 (December 2004)

  1. Added option –default-path which is used to specify the path used when finding modules. This is particularly useful when performing cross compilations (such as for building a frozen executable for Windows CE).
  2. Added option –shared-lib-name which can be used to specify the name of the shared library (DLL) implementing the Python runtime that is required for the frozen executable to work. This option is also particularly useful when cross compiling since the normal method for determining this information cannot be used.
  3. Added option –zip-include which allows for additional files to be added to the zip file that contains the modules that implement the Python script. Thanks to Barray Warsaw for providing the initial patch.
  4. Added support for handling read-only files properly. Thanks to Peter Grayson for pointing out the problem and providing a solution.
  5. Added support for a frozen executable to be a symbolic link. Thanks to Robert Kiendl for providing the initial patch.
  6. Enhanced the support for running a frozen executable that uses an existing Python installation to locate modules it requires. This is primarily of use for embedding Python where the interface is C but the ability to run from source is still desired.
  7. Modified the documentation to indicate that building from source on Windows currently requires the mingw compiler (
  8. Workaround the problem in Python 2.3 (fixed in Python 2.4) which causes a broken module to be left in sys.modules if an ImportError takes place during the execution of the code in that module. Thanks to Roger Binns for pointing this out.

Version 3.0 (September 2004)

  1. Ensure that ldd is only run on extension modules.
  2. Allow for using a compiler other than gcc for building the frozen base executables by setting the environment variable CC.
  3. Ensure that the import lock is not held while executing the main script; otherwise, attempts to import a module within a thread will hang that thread as noted by Roger Binns.
  4. Added support for replacing the paths in all frozen modules with something else (so that for example the path of the machine on which the freezing was done is not displayed in tracebacks)

Version 3.0 beta3 (September 2004)

  1. Explicitly include the warnings module so that at runtime warnings are suppressed as when running Python normally.
  2. Improve the extension loader so that an ImportError is raised when the dynamic module is not located; otherwise an error about missing attributes is raised instead.
  3. Extension loaders are only created when copying dependencies since the normal module should be loadable in the situation where a Python installation is available.
  4. Added support for Python 2.4.
  5. Fixed the dependency checking for wxPython to be a little more intelligent.

Version 3.0 beta2 (July 2004)

  1. Fix issues with locating the initscripts and bases relative to the directory in which the executable was started.
  2. Added new base executable ConsoleKeepPath which is used when an existing Python installation is required (such as for FreezePython itself).
  3. Forced the existence of a Python installation to be ignored when using the standard Console base executable.
  4. Remove the existing file when copying dependent files; otherwise, an error is raised when attempting to overwrite read-only files.
  5. Added option -O (or -OO) to FreezePython to set the optimization used when generating bytecode.

Version 3.0 beta1 (June 2004)

  1. cx_Freeze now requires Python 2.3 or higher since it takes advantage of the ability of Python 2.3 and higher to import modules from zip files. This makes the freezing process considerably simpler and also allows for the execution of multiple frozen packages (such as found in COM servers or shared libraries) without requiring modification to the Python modules.
  2. All external dependencies have been removed. cx_Freeze now only requires a standard Python distribution to do its work.
  3. Added the ability to define the initialization scripts that cx_Freeze uses on startup of the frozen program. Previously, these scripts were written in C and could not easily be changed; now they are written in Python and can be found in the initscripts directory (and chosen with the new –init-script option to FreezePython).
  4. The base executable ConsoleSetLibPath has been removed and replaced with the initscript ConsoleSetLibPath.
  5. Removed base executables for Win32 services and Win32 COM servers. This functionality will be restored in the future but it is not currently in a state that is ready for release. If this functionality is required, please use py2exe or contact me for my work in progress.
  6. The attribute sys.frozen is now set so that more recent pywin32 modules work as expected when frozen.
  7. Added option –include-path to FreezePython to allow overriding of sys.path without modifying the environment variable PYTHONPATH.
  8. Added option –target-dir/–install-dir to specify the directory in which the frozen executable and its dependencies will be placed.
  9. Removed the option –shared-lib since it was used for building shared libraries and can be managed with the initscript
  10. now checks the platform specific include directory as requested by Michael Partridge.

Version 2.2 (August 2003)

  1. Add option (–ext-list-file) to FreezePython to write the list of extensions copied to the installation directory to a file. This option is useful in cases where multiple builds are performed into the same installation directory.
  2. Pass the arguments on the command line through to Win32 GUI applications. Thanks to Michael Porter for pointing this out.
  3. Link directly against the python DLL when building the frozen bases on Windows, thus eliminating the need for building an import library.
  4. Force sys.path to include the directory in which the script to be frozen is found.
  5. Make sure that the installation directory exists before attempting to copy the target binary into it.
  6. The Win32GUI base has been modified to display fatal errors in message boxes, rather than printing errors to stderr, since on Windows the standard file IO handles are all closed.

Version 2.1 (July 2003)

  1. Remove dependency on Python 2.2. Thanks to Paul Moore for not only pointing it out but providing patches.
  2. Set up the list of frozen modules in advance, rather than doing it after Python is initialized so that implicit imports done by Python can be satisfied. The bug in Python 2.3 that demonstrated this issue has been fixed in the first release candidate. Thanks to Thomas Heller for pointing out the obvious in this instance!
  3. Added additional base executable (ConsoleSetLibPath) to support setting the LD_LIBRARY_PATH variable on Unix platforms and restarting the executable to put the new setting into effect. This is primarily of use in distributing wxPython applications on Unix where the shared library has an embedded RPATH value which can cause problems.
  4. Small improvements of documentation based on feedback from several people.
  5. Print information about the files written or copied during the freezing process.
  6. Do not copy extensions when freezing if the path is being overridden since it is expected that a full Python installation is available to the target users of the frozen binary.
  7. Provide meaningful error message when the wxPython library cannot be found during the freezing process.

Version 2.0

  1. Added support for in process (DLL) COM servers using PythonCOM.
  2. Ensured that the frozen flag is set prior to determining the full path for the program in order to avoid warnings about Python not being found on some platforms.
  3. Added include file and resource file to the source tree to avoid the dependency on the Wine message compiler for Win32 builds.
  4. Dropped the option –copy-extensions; this now happens automatically since the resulting binary is useless without them.
  5. Added a sample for building a Win32 service.
  6. Make use of improved modules from Python 2.3 (which function under 2.2)

Version 1.1

  1. Fixed import error with C extensions in packages; thanks to Thomas Heller for pointing out the solution to this problem.
  2. Added options to FreezePython to allow for the inclusion of modules which will not be found by the module finder (–include-modules) and the exclusion of modules which will be found by the module finder but should not be included (–exclude-modules).
  3. Fixed typo in README.txt.