Record/replay or "time travel" debuggers let developers record a trace of a program's execution and later replay it, allowing them to revisit past execution states and diagnose bugs that may be difficult to reproduce. These tools have existed on Linux and Windows for many years, however no such tool has ever been created for macOS. In this talk, we'll present our work towards creating a record/replay tool for macOS, describing the macOS-specific internals required to create it, why existing tools can't simply be ported, and some of the challenges that come up in creating this type of tool from scratch.