Comment by Natsu

In my case, it was egregiously bad, because someone had cribbed docs from an entirely separate scripting language that did almost the same things. Most of the same features were there, but the docs were utter lies, and failures were silent. So you'd go down the wrong branch of an if statement because it wasn't checking the conditions it claimed to check.

Once I started actually testing the scripts against the docs and rewriting them, life got so much better. The worst part is that it had been that way for years and somehow nobody noticed because the people using that horrible scripting language mostly weren't programmers and they'd just tweak things until they could happy path just enough to kinda-sorta work.