I've seen more than one half-joke-half-serious chunk of code that would "encode" arbitrary info into stack traces simply by recursively calling `fn_a`, then `fn_s`, `fn_d`, and `fn_f` before continuing with the actual intended call, giving you a stack trace with (effectively) "asdf" in it.

They've also been useful more than once, e.g. you can do that to know what iteration of a loop failed. There are of course other ways to do this, but it's hard to beat "stupid, simple, and works everywhere" when normal options (e.g. logs) stop working.

Well you're doing gods work as far as I'm concerned. Conflating difficulty in practice with impossibility in principle is, to my mind, a source of so much unnecessary cognitive error.

Similarly, one of the great things about Python (less so JS with the ecosystem's habit of shipping minified bundles) is that you can just edit source files in your site_packages once you know where they are. I've done things like add print statements around obscure Django errors as a poor imitation of instrumentation. Gets the job done!

The solution to every software problem is another layer of indirection :-)

Adversarial software development is also when I do my best work