[FreeBSD] building seafile client from sources issue

Hello.
Trying to build seafile client from sources on FreeBSD, and got an error when compiling ccnet v.5.1.4. Tried different versions of ccnet with no luck, I think, maybe I’m lacking some dependency or using wrong compiler or something? gmake & make both produce the same message. Thank for your help in advance

"
utils.c: In function ‘is_ipaddr_valid’:
utils.c:651:30: error: invalid application of ‘sizeof’ to incomplete type ‘struct in6_addr’
unsigned char buf[sizeof(struct in6_addr)];
^
utils.c:651:19: warning: unused variable ‘buf’ [-Wunused-variable]
unsigned char buf[sizeof(struct in6_addr)];
^
*** Error code 1

Stop.
make[3]: stopped in /root/seafile_build/ccnet-6.0.0-server/lib
*** Error code 1
"

Try changing
unsigned char buf[sizeof(struct in6_addr)];
to
unsigned char buf[sizeof(in6_addr)];
in file utils.c on line 651
does it work for you?