libcitadel/types.h/loff_t

I've been trying to install Citadel groupware on my Alpine Linux box and ran into a problem during the installation of libcitadel - which in some places complains about type 'loff_t' not being defined. As I found, this type is usually defined in types.h (which is also included by libcitadel, as I saw), but in Alpine it seems to be missing. I don't know if this type definition is available in kernel space and just not made available to userland or if there really is no such type definition in Alpine.

As I don't feel competent enough to screw around with system headers and libraries, I'd like to know if anyone here knows (or at least has an idea of) how to get this type to be usable via types.h (or any other means recognised by libcitadel).