Summary:

• sled Overview: Introduces sled with various resources like github repo, documentation, etc. Mentions an article about simple testing preventing critical failures.
• Error Handling in Rust: Explains Rust's error handling around Result enum and try? operator. Shows examples of error handling code and the pitfalls like repetitive code and potential bugs.
• Why Does This Matter: Discusses the tendency in the Rust community to use a single global error type. Illustrates with an example where local errors can go unhandled, leading to potential system failures.
• Case Study: sled's compare and swap error: Describes sled's error handling before and after a refactor. Before, the Error enum was a big enum with different variants, causing issues with using the try? operator. After, the signature was changed to use nested Results, improving error handling.
• Making Bugs Jump Out: Mentions strategies like using PingCAP's fail crate and property testing to trigger failures in tests and find bugs related to error handling.
• Making Unhandled Errors Unrepresentable: Concludes that keeping errors in separate types reduces the chance of try? operator pushing local concerns to inappropriate callers. Nested Results improve error handling without sacrificing code readability.
• In Summary: Warns about the tendency to use a single global error enum in the Rust community. Emphasizes the importance of separate error types for better error handling and testing. Ends with the original quotes about catastrophic system failures and error handling.