> perl compatssh2.pl 
# ctl_path: /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065, ctl_dir: /home/smokes/.libnet-openssh-perl/
# _is_secure_path(dir: /home/smokes/.libnet-openssh-perl, file mode: 16832, file uid: 1003, euid: 1003
# _is_secure_path(dir: /home/smokes, file mode: 16877, file uid: 1003, euid: 1003
# set_error(0 - 0)
# call args: ['ssh','-o','ServerAliveInterval=30','-x2MN','-o','NumberOfPasswordPrompts=1','-o','PreferredAuthentications=keyboard-interactive,password','-S','/home/smokes/.libnet-openssh-perl/user1-192.168.2.-11175-417065','-l','user1','-p',22,'192.168.2.215','--']
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# file object not yet found at /home/smokes/.libnet-openssh-perl/regression-192.168.2.-11175-417065
# tracer attached, ssh pid: 11177, tracer pid: 11178
# set_error(1 - unable to establish master SSH connection: the authenticity of the target host can't be established, the remote host public key is probably not present on the '~/.ssh/known_hosts' file)
# _kill_master: 11177
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 0, rc: 
# killing master with signal TERM
# waitpid(master: 11177) => pid: 0, rc: 
# waitpid(master: 11177) => pid: 11177, rc: Interrupted system call
# DESTROY(Net::OpenSSH=HASH(0xdb75b0), pid: <undef>)
Interrupted system callLIBSSH2_ERROR_SOCKET_DISCONNECTunable to establish master SSH connection: the authenticity of the target host can't be established, the remote host public key is probably not present on the '~/.ssh/known_hosts' file at compatssh2.pl line 13.