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

Scott Chacon’s case against Git 3.0 making SHA-256 the default is worth reading even if you disagree. NIST’s SHA-1 deadline is 2030, so the clock is real — but the migration pain is immediate: submodules only work across matching hash formats, converting a repo breaks every existing signature, and most Git libraries have zero or partial SHA-256 support. He’d rather sign both hashes in a tree-hash header than split the ecosystem in two.