makedepends field of alpm_pkg_t

Hi guys, I have a brief question about the `makedepends` field of the `alpm_pkg_t` type. Try as I might, I'm unable to get this field to report anything (i.e. a non-empty alpm_list) for installed packages originally from the AUR that definitely had makedepends. This seems to be the case even when those makedepends are still installed. Under what circumstances should this field be expected to yield results? To be clear, I'm accessing it via the top-level `_pkg_get_makedepends` function. Thanks, Colin