I saw an example the other day that escapes annoyingly escapes my mind now, as it has been sort of overwritten by the "why the heck do some people name Makefile

I saw an example the other day that escapes annoyingly escapes my mind now, as it has been sort of overwritten by the "why the heck do some people name Makefiles with a capital M!?" pet peeve. But I'd say a bit of everything listed in TFA. For instance global variables are the type of thing which makes a little voice say "if you do that, something bad will eventually happen". The voice of experience sometimes say things like that, though.