I started by looking everywhere I thought I called printf in this particular case, and couldn't find a single problematic printf. Given the input I was using, I thought I knew where the printf was probably going to be. But that failed, and there are hundreds throughout the rest of the program. (I use them for generating output and warning/error messages--- I happen to like the format string method of describing your output.)
Then I thought, I sure would like to learn more about the debugger and profiling, so I thought it was worth asking. I never have gotten clear on how to compile libraries for profiling.
While waiting for a reply here, it struck me where the printf was, and I found it and solved the problem. So there's not an immediate need for the stack trace.
D