Bun 1.4 Rust rewrite is not looking good

Bun's v1.4 Rust rewrite is facing significant challenges, with the project missing release deadlines for three months while the lead developer makes repeated false promises about shipping dates, causing community frustration. The rewrite heavily relies on AI-generated code (with Claude generating most commits while human contributions dwindle), has accumulated over 5,000 open pull requests—far exceeding GitHub's recommended limits—and raises concerns about code quality according to Zig creator Andrew Kelley.