Thanks for your comment. Yes, I understand your concern and I second your opinion that print statements for debugging are a bad idea, one of the reasons I looked into using callbacks that could allow the test software to inspect intermediate results within a sub. There are some situations (e.g. "large amount of state data shared among the different steps of a function" see 880089) in which intermediate values inside a sub need to be evaluated, but instead of printing these ase debug statements I have been using a "test point" analogy that I describe here 882331. This allows a your test to diagnose the problem better before firing up the debugger to fix it.

Of course many of this situations can be avoided with better design, but in the real world time and budget constraints don't allow for adequate refactoring to fix these design problems. The test point idea was precisely for eliminating all these print-debug statements and move these intermediate values to be evaluated in the test suite instead of reading and making sense of all the verbose debug statements.