OSS + ELC EU 2026

Defined as bugs which disappear or change behavior when observed, every embedded engineer has come across one at some point. Some classic examples include bugs that stop reproducing after adding printk() statements, introducing new variables, connecting a debugger or even simply recompiling the same source code. The root causes of Heisenbugs range all the way from race conditions, memory corruption, alignment issues, cache incoherency, incorrect linker configurations to even hardware bugs.

This talk walks through the debugging techniques which could be applied for debugging these Heisenbugs like static code analysis, memory analysis, diagnostic data collection, tracing and instrumentation, selective elimination of unrelated code paths, modifying assembly instructions at runtime; all without probing the observer’s effect. Beyond techniques, the talk aims to develop the intuition and thought process needed when confronting these bugs. The talk discusses how to distinguish between mere workarounds that mask the underlying issue vs actual fixes. Practical experiences in debugging real Heisenbugs will be shared along with their root causes, investigation approaches and the fixes.