Heisenbug: When the Bug Knows You're Watching

Heisenbug: a software bug that seems to disappear or alter its behavior the exact moment you try to observe or analyze it.

During an internal development project we ran into one of these mythical creatures. We could reliably reproduce the problem in the running application, but the second we attached a debugger, the bug vanished!

What followed was an investigation lasting several days, full of red herrings and surprises.

In this talk we condense that journey into 30 minutes and guide you through the process we used to track down a bug that refused to be debugged. It will be an interactive session: we’ll invite you to form hypotheses alongside the rest of the audience. Will you solve the mystery before we reveal the answer?

More than a simple bugfixing tale, this session presents a hands-on approach to analyzing elusive, non-deterministic issues, providing a practical framework to tackle even the most tricky debugging scenarios with confidence.