War story: the hardest bug I ever debugged

(www.clientserver.dev)

462 points jakevoytko | 1 comments | 24 Mar 25 14:37 UTC | HN request time: 0s | source

Show context

BobbyTables2 ◴[27 Mar 25 03:27 UTC] No.43490119[source]▶

>>43461618 (OP) #

Interesting writeup, but 2 days to debug “the hardest bug ever”, while accurate, seems a bit overdone.

Though abs() returning negative numbers is hilarious.. “You had one job…”

To me, the hardest bugs are nearly irreproducible “Heisenbugs” that vanish when instrumentation is added.

I’m not just talking about concurrency issues either…

The kind of bug where a reproduction attempt takes a week, not parallelizable due to HW constraints, and logging instrumentation makes it go away or fail differently.

2 days is cute though.

replies(13): >>43490149 #>>43490287 #>>43490459 #>>43490557 #>>43491079 #>>43491823 #>>43492539 #>>43492555 #>>43492647 #>>43493115 #>>43493245 #>>43493811 #>>43497018 #

efortis ◴[27 Mar 25 05:12 UTC] No.43490557[source]▶

>>43490119 #

Same here, we had an IE8 bug that prevented the initial voice over of the screen reader (JAWS). No dev could reproduce it because we all had DevTools open.

replies(2): >>43493509 #>>43494922 #

1. gsck ◴[27 Mar 25 15:52 UTC] No.43494922[source]▶

>>43490557 #

I had a similar issue, worked fine when I was testing it on my machine, but I had dev tools open to see any potential issues.

Turns out IE8 doesn't define console until the devtools are open. That caused me to pull a few hairs out.

↑