The documentation for this release is at https://pyoxidizer.readthedocs.io/en/pyoxidizer-0.21.0/pyoxidizer.html.

Backwards Compatibility Notes

• The minimum Rust version has been changed from 1.56 to 1.60 to facilitate
  use of features required by some Rust crates.
• The default Python version is 3.10 (instead of 3.9).

Bug Fixes

• Fixed regression in the behavior of various pyoxidizer commands which
  prevented them from working without specifying any arguments. This regression
  was introduced in 0.20 with the upgrade of the clap crate to version 3.1.
  (#523)
• PyO3 Rust crates upgraded from 0.16.4 to 0.16.5. The upgrade fixes compatibility
  issues with Python 3.10 that could lead to runtime crashes or incorrect behavior
  in many configurations.
• Fixed a runtime panic when incorrect attribute assignments were attempted on the
  PythonExtensionModule, PythonPackageDistributionResource, and
  PythonPackageResource Starlark types. (#561)
• We no longer panic when encountering invalid UTF-8 when reading process output
  of various python invocations. Previously, invocations of pip,
  setup.py, and other processes could result in a panic if invalid UTF-8 was
  emitted. (#579)

New Features

• Default CPython distributions upgraded from 3.8.12, 3.9.10, and 3.10.2
  to 3.8.13, 3.9.13, and 3.10.4, respectively. See additional changes in
  these distributions at
  https://github.com/indygreg/python-build-standalone/releases/tag/20220318,
  https://github.com/indygreg/python-build-standalone/releases/tag/20220501,
  and https://github.com/indygreg/python-build-standalone/releases/tag/20220528.

• The default Python version is now 3.10 (instead of 3.9).

• The mechanism for handling software licenses has been overhauled.

  • The formatting of licenses during building has changed significantly.
  • Rust licensing information is now dynamically derived at build time rather
    than derived from a static list. The Rust components with annotated licensing
    should be more accurate as a result.
  • PythonExecutable Starlark types now write out a file containing
    licensing information for software components within the binary. This restores
    a feature that was dropped in version 0.5. The name of the file (or disabling
    of the feature) can be controlled via the
    PythonExecutable.licenses_filename attribute.
  • A new pyoxidizer rust-project-licensing command for printing licensing
    information for Rust projects. This can be used to help debug Rust licensing
    issues or to generate licensing content for any Rust project.
  • A PythonExecutable.add_cargo_manifest_licensing Starlark method for
    registering the licensing information for a Cargo.toml Rust project. This can
    be used by Rust projects wishing to have their licensing information captured.

• Initial support for aarch64-unknown-linux-gnu Python distributions. The
  distributions are now defined and PyOxidizer should use them when appropriate.
  However, the distributions aren't yet well tested. So feedback on their
  operation via GitHub issues would be appreciated!

• aarch64-apple-darwin (Apple M1) now has a default Python 3.8 distribution.
  This distribution is not very well tested and use of a Python 3.9+ for Apple M1 is
  strongly advised.

Other Relevant Changes

• Managed Rust toolchain upgraded from 1.56.1 to 1.61.0.
• Starlark PythonInterpreterConfig documentation has been changed
  to refer to pyembed_interpreter_config. The latter is automatically
  derived from the canonical Rust source code. So the change effectively results
  in a single, consistent set of documentation for interpreter configuration.
• The mechanism for locating the Apple SDK now uses the
  apple-sdk Rust crate. The new crate
  work similarly to how our custom logic was working before. But there may be
  subtle changes in behavior. If you see new build errors related to Apple SDKs
  in this release, don't hesitate to create an issue. One notable change is that
  we will now look for SDKs in all /Applications/Xcode*.app directories. In
  environments like GitHub Actions, this will result in finding and using the
  newest installed SDK.
• The jemalloc allocator in built binaries has been upgraded to version 5.3.
• The auto-generated Rust project created during binary building is now explicitly
  licensed to the public domain.
• Derivation of a custom libpython library archive now sometimes uses pure
  Rust code instead of calling external processes. There should be no meaningful
  change in behavior except for build output being more concise.
• Auto-generated Rust projects now contain an empty [workspace] table in their
  Cargo.toml. This enables auto-generated projects to be nested under an existing
  workspace directory without Cargo complaining. This approach is more robust in
  the common case where the Rust project isn't part of a larger workspace.
• See https://github.com/indygreg/PyOxidizer/releases/tag/oxidized_importer%2Fpython-oxidized-importer%2F0.6.0 for relevant changes in the oxidized_importer extension module.