programming fuck ups

What's the biggest screw up you ever made writing software?  Once a team I was on overshot a DCUT for some datacenter automation tools by two weeks, and it still ended up being shitty because the customer kept wanting to add shit.

I was writing something in C which required a big complex loop calling a bunch of functions for several different procedures that had to be done. I was perplexed that a certain variable would always get incremented and it shouldn't. I analyzed every function, came to the conclusion that all were right, and then focused on the loop itself. I debugged the program, step-by-step. Every time I was more and more pissed at it, and I ended up reviewing the fucking assembly code. Then I saw how it would clearly get incremented. I got to the point of thinking gcc had to have a bug. When I was about to try rewriting it somehow to prevent it from happening, I noticed:


while (...) {
    ...big loop...
    ...lots of stuff...
    ...function calls...
    ...etc...

j++;
}

I wasted an evening with that. Fucking stupid. Had my vision checked after it.