Bun 1.4 Rust rewrite is not looking good

Bun’s 1.4 rewrite, now in Rust, has generated over 15,800 commits from the “robobun” bot and 1,600 from an autofix CI bot, leaving more than 5,000 open pull requests—far exceeding GitHub’s recommended limit of 1,000. Critics note numerous unsafe Rust blocks and “hacks on top of hacks,” suggesting the rewrite fails to deliver the promised memory-safety improvements and appears driven by Anthropic’s AI-coding ambitions rather than technical necessity.