During September 2013, Ernie Miller enhanced error handling in the ruby/ruby repository by improving how Ruby surfaces comparison failures. He modified the core C implementation to add a reason parameter to the rb_cmperr function, enabling more precise and actionable error messages when comparisons fail due to nil values or coercion issues. This change clarified failure contexts in common operations such as Array#sort, making debugging more straightforward for developers. By focusing on C programming, debugging, and error handling, Ernie’s work improved the clarity and consistency of user-facing error reports, reducing triage time and enhancing the overall developer experience in Ruby core.