MIO - Multiverse Debugging in the Face of Input/Output

Explore a 14-minute conference presentation from OOPSLA 2025 that introduces a groundbreaking approach to debugging non-deterministic programs on microcontrollers. Learn about the challenges of debugging programs with input/output operations using traditional multiverse debugging techniques, which can lead to inaccessible program states that hinder the debugging process. Discover how the novel MIO (Multiverse Debugging in the face of Input/Output) approach addresses these limitations by accommodating a broad spectrum of input/output operations while ensuring that only reachable program states are explored during debugging. Examine the formal semantics and correctness proofs that guarantee the debugger's reliability, and understand how the prototype implementation leverages the WARDuino WebAssembly virtual machine for efficient debugging on embedded systems. See a practical demonstration featuring a color dial built with Lego Mindstorms components running on an STM32 microcontroller, showcasing how this approach enables effective multiverse debugging for real-world embedded applications with sensors and actuators.