libzfs.h and libnvpair.h

Hello,

I am working into bringing the checkpoint functionality for bhyve and I
think I could use the zfs functionalities for the implementation. I tried
to build the world with -DWITH_ZFS and -DWITH_CDDL(I don't exactly know
what macro or macros should be defined or if there are any, these two I
tried based on the analysis of the Makefiles) but this doesn't seem to
work. When I include libzfs.h in order to use the functions from there, I
get a compilation error saying that libnvpair.h is not found. After
investigating the problem I saw that in /usr/include libnvpair.h is not
present. I copied the files from /usr/local/include but after this there
was a problem with the redefinition of some functions. Is it a way to
use(or 'activate') the zfs functionalities directly in the code without
using syscalls like system or exec(I would like to avoid them as much as
possible).

Thank you.