https://pydevtools.com/tags/python/ The Python Developer Tooling Handbook is a comprehensive guide to Python development tools including uv, ruff, pytest, mypy, ty, and more. Hugo -- gohugo.io en Mon, 11 May 2026 09:00:00 -0400 https://pydevtools.com/blog/python-3145-rolls-back-the-incremental-garbage-collector/ Mon, 11 May 2026 09:00:00 -0400 Tim Hopper https://pydevtools.com/blog/python-3145-rolls-back-the-incremental-garbage-collector/ <p>Python 3.14.5 <a href="https://blog.python.org/2026/05/python-3145-is-out/"target="_blank" rel="noopener">landed on 10 May 2026</a>, pulled the incremental garbage collector that shipped in 3.14.0 through 3.14.4, and put the 3.13 generational collector back. Patch releases almost never reverse a major implementation change. The <a href="https://docs.python.org/3.14/whatsnew/3.14.html#garbage-collection"target="_blank" rel="noopener">What&rsquo;s New page</a> names the cause: &ldquo;due to a number of reports of significant memory pressure in production environments, it has been reverted back to the generational GC from 3.13.&rdquo;</p> <h2>Recap what the incremental collector promised<span class="hx:absolute hx:-mt-20" id="recap-what-the-incremental-collector-promised"></span> <a href="#recap-what-the-incremental-collector-promised" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p><a href="https://pydevtools.com/handbook/explanation/what-is-python/">CPython</a> collects cyclic garbage with a tracing collector that runs alongside refcounting. Up through 3.13, that collector was generational with three generations. Objects that survived a collection moved up a generation, and the collector visited older generations less often. A full collection of the oldest generation traced every object the program kept alive, which on long-running processes produced multi-hundred-millisecond pauses.</p>