Good point, but the optional argument to argname can be used to
prevent breakage:

string realname = argname(depY, "depY")

> If what you want is be sure that what your function prints makes
> sense I would suggest to fine-tune the printout using tools like
> printf, sprintf() and modprint, which give you complete control on
> what to print and how. [...]

Agreed, that's the clean solution.