Git considers SHA-256, Rust, LLMs, and more (lwn.net)

Git maintainers are accelerating work toward a 3.0 release (targeted around 2026) with three major shifts: a default move from SHA-1 to SHA-256, a growing adoption of Rust, and a restrictive stance on code produced by large language models. The SHA-256 transition is motivated by SHA-1’s dwindling security; Git has supported SHA-256 since v2.29 (2020), but real-world use requires extensive interoperability between SHA-1 and SHA-256 repositories. Brian M. Carlson has driven most of that work and estimates 200–400 patches are needed (≈100 done), so finishing the effort will require more contributors and coordination with repository forges. Concurrently, Rust is being introduced progressively—examples include a Rust xdiff reimplementation and a Patrick Steinhardt patch series that adds an optional Rust module and documentation indicating Rust will become mandatory for building Git by 3.0, plus CI changes to test Rust builds. For the AI/ML community, Git’s emerging policy on LLM-assisted contributions matters: maintainers worry about legal provenance (Developer’s Certificate of Origin), hallucinations, and poor-quality code. Proposed rules would reject submissions that appear AI-generated or that contributors can’t explain, and Junio Hamano has proposed a firmer QEMU-style stance. Other notable changes include switching the default branch name to “main,” data-model docs from Julia Evans, and continued maintenance focus—signals that Git’s evolution will affect tooling, security workflows, and how AI-assisted development is accepted in open-source projects.