Theo Zimmermann worked on stabilizing the Rocq Hierarchy Builder within the coq/opam repository, focusing on ensuring compatibility with Coq 1.9. He addressed dependency management challenges by adjusting version ranges for coq-elpi and rocq-elpi, resolving build conflicts that previously hindered stable releases. His technical approach centered on refining package management processes in OCaml, which improved the predictability and maintainability of the build environment. Over the course of the month, Theo fixed a critical bug related to dependency constraints, demonstrating depth in managing complex package interactions and contributing to a more robust and reliable opam pipeline for the Coq ecosystem.