Python 3.8 End-of-Life And Build Tool Impact

Hey everyone! Let's dive into a pretty significant topic that's on the horizon for us Python developers: the upcoming end-of-life (EOL) for Python 3.8 and what that means, especially for our build processes and tools like cibuildwheel and manylinux.

Why Python 3.8 is Saying Goodbye

First off, Python 3.8 officially reached its end-of-life on October 7, 2024. Now, for many of you, this might sound like ancient history, but surprisingly, Python 3.8 is still quite prevalent. According to the latest stats, it's used to produce wheels for a substantial 35% of active projects. Now, before you panic, the good news is that py3 or abi3 wheels won't be as directly impacted by the upcoming changes. Still, it's a big chunk of the ecosystem!

The manylinux Timeline and Its Implications

The manylinux project, which is super crucial for creating binary wheels that work across various Linux distributions, has set a date: May 5, 2026. That's the day they plan to officially drop support for Python 3.8 builds. Why this date? Well, it aligns nicely with the release of CPython 3.15.0b1 and gives folks a good heads-up, about five months, to provide feedback and make adjustments. This timeline is critical because manylinux builds are the backbone for a huge number of Python packages distributed as wheels. When manylinux makes a change like this, it ripples through the entire Python packaging ecosystem, and tools like cibuildwheel are directly affected.

Understanding the manylinux Decision

The decision to drop Python 3.8 from manylinux builds isn't taken lightly. It's driven by the natural lifecycle of software and the need to focus resources on supporting newer, actively maintained versions of Python. As Python versions reach their EOL, maintaining builds for them becomes increasingly challenging and less secure. Security vulnerabilities are often patched in newer releases, and older versions stop receiving these critical updates. For manylinux, this means they have to keep maintaining older build environments and testing infrastructure for a version that's no longer officially supported by CPython itself. This drains resources that could be better used to improve support for current and future Python versions.

The Impact on Package Maintainers and Users

So, what does this mean for us, the everyday package maintainers and users? If you're still building or distributing wheels for Python 3.8, you'll need to plan for this transition. After May 5, 2026, you won't be able to rely on manylinux to generate Python 3.8 compatible wheels. This might mean you'll need to:

• Update your build infrastructure: Ensure your CI/CD pipelines are configured to build against newer Python versions.
• Consider alternative build strategies: If you absolutely must support Python 3.8 for a while longer, you might need to explore other methods for building wheels, though this could become more complex and less portable.
• Communicate with your users: Let your users know about the EOL and any potential changes in how they can install your package, especially if they are on older systems.

For users, this primarily means that new packages or updated versions of existing packages might not be available as pre-compiled wheels for Python 3.8 after this date. They might need to compile from source, which can be a more involved process and might require development tools that aren't readily available on their systems.

Key Dates and What They Mean

Let's break down the important dates we've discussed:

• October 7, 2024: Python 3.8 EOL. This is the official date where Python 3.8 stopped receiving new features and bug fixes. While not a hard stop for usage, it's a clear signal for the community to migrate.
• May 5, 2026: manylinux drops Python 3.8 builds. This is the date you really need to mark on your calendar if you rely on manylinux wheels. After this, you won't get new Python 3.8 wheels generated through this system.
• April 2, 2025: Standard support ends for Ubuntu 20.04. This is relevant because Ubuntu 20.04 is a popular OS that still uses Python 3.8. While extended support continues, relying on standard support ending is another nudge towards newer systems.
• June 30, 2026: Amazon Linux 2 EOL. Another significant platform where Python 3.8 is common. Its EOL date is close to the manylinux drop date, suggesting a coordinated shift away from these older environments.

Why These Dates Matter

These dates aren't arbitrary. They are carefully chosen to allow for a smooth transition. The EOL of Python 3.8 means that the Python core development team will no longer be actively fixing bugs or security issues in this version. Relying on an EOL version poses security risks and can lead to compatibility issues with newer libraries and tools. The manylinux date is strategically placed to give the community ample time to adapt. It also coincides with a CPython release milestone, indicating a natural point for such a transition in the build tooling space.

The Role of cibuildwheel

Now, let's talk about cibuildwheel. This tool is a lifesaver for many of us who need to build wheels across different platforms and Python versions. cibuildwheel heavily relies on manylinux images for building Linux wheels. Consequently, when manylinux decides to drop support for a specific Python version, cibuildwheel will naturally follow suit. The issue linked in the original prompt (pypa/manylinux/issues/1882) is specifically created to get more visibility on this impending change and its direct impact on cibuildwheel.

How cibuildwheel is Affected

If you use cibuildwheel in your CI/CD pipelines to generate wheels, you'll need to pay attention to its configuration. As manylinux images are updated, cibuildwheel will start using newer base images. This means that if your pipeline is still explicitly targeting Python 3.8 with cibuildwheel after the manylinux cutoff, your builds might start failing or producing incompatible wheels. It's essential to update your cibuildwheel configurations to only build for supported Python versions. This usually involves adjusting the python_version or similar settings in your CI configuration files (like .github/workflows/build.yml or .travis.yml).

Migrating Your cibuildwheel Setup

For most users, migrating away from Python 3.8 in cibuildwheel will be straightforward. It typically involves removing Python 3.8 from the list of versions you're building for. For instance, if you had something like:

CIBW_PYTHON_VERSION=3.8 3.9 3.10 3.11

You would simply update it to exclude 3.8, perhaps like this:

CIBW_PYTHON_VERSION=3.9 3.10 3.11 3.12

Remember to test your builds thoroughly after making these changes to ensure everything still works as expected. You might also want to update your project's setup.py or pyproject.toml to reflect the minimum supported Python version if it was previously set to 3.8 or lower.

The Bigger Picture: Staying Current

This whole situation with Python 3.8's EOL and the subsequent changes in build tooling is a great reminder of why staying current with Python versions is so important. Keeping your projects on actively supported Python versions not only gives you access to new features and performance improvements but also ensures you receive critical security updates and benefit from the ongoing work of the community and tool maintainers.

Why Modernize?

• Security: EOL versions don't get security patches. Using them is like leaving your digital doors unlocked.
• Features: Newer Python versions come with exciting new features that can make your code cleaner, more efficient, and more readable.
• Performance: Each Python release often brings performance enhancements that can make your applications faster.
• Ecosystem Support: Libraries, frameworks, and tools like manylinux and cibuildwheel inevitably drop support for older Python versions to focus their efforts. Staying current ensures you can leverage the latest and greatest from the entire Python ecosystem.
• Community: When you use an EOL version, you're outside the main support channel. Finding help or solutions might become harder.

What About Downloads?

It's interesting to note that Python 3.8 currently accounts for less than 5% of overall manylinux wheels downloads. While this might seem small, it's still a significant number of users. However, the downward trend is clear, and this is precisely why manylinux and other tools are moving forward. The majority of users have already migrated or are in the process of migrating, making it more efficient to focus resources on these users and newer Python versions.

Preparing for the Transition

So, guys, what's the game plan? Here's how you can get ready:

1. Assess your project's Python version support: Check your setup.py or pyproject.toml to see what Python versions your project claims to support.
2. Update your CI/CD pipelines: Modify your cibuildwheel configurations and any other build scripts to remove Python 3.8.
3. Test thoroughly: After updating, run your full test suite to catch any unexpected issues.
4. Monitor dependencies: Keep an eye on your project's dependencies. As they update, they'll likely drop support for older Python versions too.
5. Educate your users: If your project is widely used, communicate the upcoming changes and guide users on how to update if necessary.

The transition away from Python 3.8 is a natural and necessary step in the evolution of the Python ecosystem. By understanding the timelines, the impact on our tools, and the benefits of staying current, we can all navigate this change smoothly and ensure our projects remain secure, efficient, and well-supported. Let's embrace the future of Python, shall we?