make: *** [tunnel] Error 1

[malik1230]

make error on Ubuntu 18.04.4 LTS (Bionic Beaver), requested for help,

root@Ubunto:~/Obfuscation-Tunnel# make
g++ -std=c++14 -Wall -Wextra -Ofast -DHAVE_PCAP=1 -lpcap -lpthread -lssl -lcrypto main.cpp -o tunnel
In file included from factory.cpp:4:0,
from main.cpp:1:
udp_client.cpp: In member function 'int udp_client::_handshake()':
udp_client.cpp:88:18: warning: variable 'fatal' set but not used [-Wunused-but-set-variable]
bool fatal = false;
^~~~~
In file included from factory.cpp:8:0,
from main.cpp:1:
tcp_server.cpp: In member function 'int tcp_server::_accept()':
tcp_server.cpp:97:22: warning: variable 'fatal' set but not used [-Wunused-but-set-variable]
bool fatal = false;
^~~~~
/tmp/ccaE02sd.o: In function `ssl_gen_cert(char const*, x509_st**, evp_pkey_st**)':