Compiler optimizations can cause surprising behavior. When a function
has called another function as its final action (a @dfn{tail call}), the
calling function may not appear in a backtrace at all. Similarly, when
Compiler optimizations can cause surprising behavior. When a function
has called another function as its final action (a @dfn{tail call}), the
calling function may not appear in a backtrace at all. Similarly, when