The worst frustration I ever had was co-writing a program with someone who would change the library we were both linking to without telling me it had changed. That meant my calls to routines were missing variables or had added variables or worse, the code would crash in the library that I didn't have access to. And when we worked at different times ... it meant I was only half able to do the work.

A secondary one was when I was required to provide third level help desk assistance--this meant days would go by before I actually got to write the code I was working on. So I learned to always keep a list of what I was doing and where I was.

A third one was when I was asked to process a set of data for which I didn't have the specs and the people I worked with wouldn't give them to me, so I spent a lot of time figuring out how to change octal values and annoying stuff like that.

A fourth was having to make changes to code provided by someone else, and then never got around to making the changes we had made to make it work, so the coding was all about retyping in old changes on a new release. Boring.