$ ./configure --enable-server --enable-proxy --enable-agent --enable-ipv6 --with-net-snmp --with-unixodbc --with-libxml2 --with-libcurl --with-openipmi --with-postgresql --with-openssl --with-ldap --with-libevent=/home/zabbix34/libevent-2.1.8-install --prefix=`pwd`
$ make install
--------------------------------------------------
...
In file included from /home/zabbix34/libevent-2.1.8-install/include/evutil.h:37:0,
                 from /home/zabbix34/libevent-2.1.8-install/include/event.h:57,
                 from ../../../include/sysinc.h:381,
                 from ../../../include/common.h:23,
                 from ipcservice.c:1:
/home/zabbix34/libevent-2.1.8-install/include/event2/util.h:312:25: error: two or more data types in declaration specifiers
 #define evutil_socket_t int
                         ^
ipcservice.c:60:13: note: in expansion of macro ‘evutil_socket_t’
 typedef int evutil_socket_t;
             ^~~~~~~~~~~~~~~
ipcservice.c:60:1: warning: useless type name in empty declaration
 typedef int evutil_socket_t;
 ^~~~~~~
ipcservice.c:62:22: error: static declaration of ‘event_new’ follows non-static declaration
 static struct event *event_new(struct event_base *ev, evutil_socket_t fd, short what,
                      ^~~~~~~~~
In file included from /home/zabbix34/libevent-2.1.8-install/include/event.h:69:0,
                 from ../../../include/sysinc.h:381,
                 from ../../../include/common.h:23,
                 from ipcservice.c:1:
/home/zabbix34/libevent-2.1.8-install/include/event2/event.h:1080:15: note: previous declaration of ‘event_new’ was here
 struct event *event_new(struct event_base *, evutil_socket_t, short, event_callback_fn, void *);
               ^~~~~~~~~
...	       
ipcservice.c: At top level:
ipcservice.c:74:13: error: static declaration of ‘event_free’ follows non-static declaration
 static void event_free(struct event *event)
             ^~~~~~~~~~
In file included from /home/zabbix34/libevent-2.1.8-install/include/event.h:69:0,
                 from ../../../include/sysinc.h:381,
                 from ../../../include/common.h:23,
                 from ipcservice.c:1:
/home/zabbix34/libevent-2.1.8-install/include/event2/event.h:1131:6: note: previous declaration of ‘event_free’ was here
 void event_free(struct event *);
      ^~~~~~~~~~
--------------------------------------------------

0.3. Compatibility

  Our source-compatibility policy is that correct code (that is to say,
  code that uses public interfaces of Libevent and relies only on their
  documented behavior) should have forward source compatibility: any
  such code that worked with a previous version of Libevent should work
  with this version too.