(*) Caveat: It must be a small challenge involving a relatively simple task. I don't have a lot of time to waste on this.
Nice caveat. Let me rephrase that another way for you: it is difficult to implement complicated functionality in C. Indeed, this is one reason to use higher level languages. You can achieve more in less time.
At the source of every error which is blamed on the computer you will find at least two human errors, including the error of blaming it on the computer.