devkitPro

I'm a bit confused - what relevance does the age of your libc have here? It's not clear if you mean that you're getting link errors from code compiled with devkitARM or if you have recompiled devkitARM with profiling and g++ itself is missing calls to this function.

I could have a guess but really I'd like to clarify what exactly is happening before getting too deep into technical stuff.