I build the libzdb/libevhtp/libsearpc/ccnet according to the guide manual, but failed to build the seafie-server due to the failure on reference "bufferevent_openssl_socket_new" in libevhtp.a, I check the code of evhtp.c and openssl.h without luck to find out where the function is defined. libevhtp can be pass the build without error, but seafile-server can't(If I comment out this function in evhtp.c, all of the builds can be passed). Does anyone know how to solve the build error as below? Thanks.

detail error:

/usr/local/lib/libevhtp.a(evhtp.c.o): In function evhtpaccept_cb':
evhtp.c:(.text+0x511a): undefined reference tobufferevent_openssl_socket_new'
/usr/local/lib/libevhtp.a(evhtp.c.o): In function evhtprun_in_thread':
evhtp.c:(.text+0x5310): undefined reference tobufferevent_openssl_socket_new'
collect2: error: ld returned 1 exit status
make[3]: *** [seaf-server] Error 1
make[3]: Leaving directory /home/jiajiesun/fileserver/code/seafile-4.0.6-server/server'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory/home/jiajiesun/fileserver/code/seafile-4.0.6-server/server'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/jiajiesun/fileserver/code/seafile-4.0.6-server'
make: *** [all] Error 2