Biggest time loss bug

Question

We've all had them, errors or bugs that have lost us lots of time. I've seen it time and time again, the first 90% of the coding work for a given project takes 10% of the total time. It's that last 90% of the time you spend looking for that rogue bug that's really only about 10% of the coding work. That one thing that just doesn't want to work. Sometimes it's something big and other it's just that one character that was off.

What is the bug or error that has cost you and/or your team the most amount of time?

Answer 1

Getting Oracle to work, we are a SQL shop and now have to support Oracle, and nobody knew anything about Oracle.

Answer 2

Ive spent over 2 days trying to figure out a CSS issue that was breaking my site. It turned out to be that I mistook a curly brace for a parenthesis in one of the classes and my resolution is set too small to be able to tell very easily

Answer 3

Debugging some error that the Yahoo user interface library was spitting out. Spent a couple of days on it. It turned out that YUI spits out errors that are supposed to happen and don't need fixing.

Answer 4

3 months trying to track down an error in our engine rendering code. We had implemented our own custom vertex-pooling scheme, and it worked great in DX8. Once I upgraded the engine to DX9, all the geometry came out as garbled messes. Luckily I was able to turn that off with a #define, but hunting it down was a painful month of trial and error, and in the end it boiled down to setting the wrong parameter in an interface function that had changed in DX9 - we were setting firstvertex instead of startvertex, which caused the index lists to read the wrong vertices. Fun stuff.

Answer 5

Once upon a time, I worked on a database project for an apartment management company. We had tables like Customer, CustomerStatus, Apartment, ApartmentStatus, and so forth. Queries I wrote would look like:

SELECT cu.Name, ap.ApartmentUnit, as.DateOccupied
 from Customer cu
  inner join CustomerStatus cs
   on cs.CustomerId = cu.CustomerId
  inner join ApartmentStatus as
   on as.ResidentId = cu.CustomerId
    and as.Status = 5
  inner join Apartment ap
   on ap.ApartmentId = as.ApartmentId
 where cu.CustomerId = @CustomerId

This query and ones like it simply would not run, no matter how hard I tried, modified, or stared at it. It took days before I realised that my entirely reasonable table alias of "as" was a reserved word...

Answer 6

A Heisenbug is IMO one of the worst bug. Hunting such a beast is a real nightmare. Having that said, a Bohrbug, a Mandelbug, a Schroedinbug, a Phase of the Moon bug or a Statistical bug will give you serious headache too.