Git 3.0's upcoming SHA-256 default will be a costly mistake

Git 3.0 will switch its default content hashing algorithm from SHA-1 to SHA-256 due to theoretical collision vulnerabilities discovered in SHA-1, but the author argues this change will impose massive costs on the global Git community for minimal practical benefit. While SHA-1 has never experienced actual collisions in billions of existing repositories over 20 years, the mathematical weakness makes the transition seem necessary despite the enormous disruption it will cause.