[derleth]

> messing them up creates bugs

Messing them up exposes bugs that are likely to bite you in other ways. If you can't get malloc()/free() right, you don't really 'get' the flow control/data flow through your program yet and that is a problem.

[tptacek]

Arena allocation is inherently simpler and less error-prone than demand-allocating and demand-freeing. It's not valid to say that arena allocation is "hiding" bugs; what it's doing is foreclosing on the possibility of having those bugs.

Virtually no large project has ever gotten malloc/free completely right in its first revision; for the past 20 years or so, most projects get this wrong to the tune of "remote code execution".