The system is running stable/12 amd64 r365314.
/usr/src is at r367707.
/usr/ports is at r555451.

--- dnode2.o ---
In file included from dnode2.c:62:
In file included from /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_znode.h:33:
In file included from /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h:48:
In file included from /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zfs_context.h:73:
In file included from /usr/src/sys/cddl/compat/opensolaris/sys/vfs.h:37:
/usr/src/sys/cddl/compat/opensolaris/sys/vnode.h:243:10: warning: implicit declaration of function 'VOP_FSYNC' is invalid in C99 [-Wimplicit-function-declaration]
        error = VOP_FSYNC(vp, MNT_WAIT, curthread);
                ^
/usr/src/sys/cddl/compat/opensolaris/sys/vnode.h:281:61: error: too many arguments to function call, expected 5, have 6
        return (kern_unlinkat(curthread, AT_FDCWD, fnamep, seg, 0, 0));
                ~~~~~~~~~~~~~                                      ^
/usr/include/sys/syscallsubr.h:298:1: note: 'kern_unlinkat' declared here
int     kern_unlinkat(struct thread *td, int fd, char *path,
^
1 warning and 1 error generated.
*** [dnode2.o] Error code 1