The Crash That Only Happened in Production
The crash was intermittent, production-only, and invisible to every test I ran locally. It turned out to be a data race in code a free coding model wrote for me, and the fix was a single lock. This post walks the symptom-to-root-cause trail and shows how the Go race detector made the invisible visible. I used MonkeyCode's free model access to generate a small concurrent log aggregator for a side…
A production-only crash, invisible during local testing, was discovered to be caused by an intermittent data race in code generated by a free coding model. The issue was traced using the Go race detector, which made the invisible bug visible. The reporter used MonkeyCode's free model access to create a concurrent log aggregator for a side project and previewed it on the free server option.
The bug arose due to concurrent map writes without synchronization, leading to the fatal error: concurrent map writes. The fix involved wrapping the map in a mutex to ensure safe access. The reporter emphasized the importance of treating every agent-written map as a suspect until proven otherwise, especially when experimenting with free model access and free servers.
Enabling the race detector during testing can help catch class of bugs that only appear under load, providing valuable insights without significantly impacting the test suite's performance.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
