# io3 mloop, cin: 0, cout: 1, cerr: 0
# io3 fast, cin: 0, cout: 1, cerr: 0
# stdout, bytes read: 20 at offset 0
#> 45 78 69 74 20 72 65 71 75 65 73 74 20 73 65 6e 74 2e 0d 0a        
+                             | Exit request sent...
# io3 fast, cin: 0, cout: 1, cerr: 0
# stdout, bytes read: 0 at offset 20
# leaving _io3()
# _waitpid(19779) => pid: 19779, rc:
# _kill_master: 19774
# waitpid(master: 19774) => pid: 19774, rc:
# call args: ['ssh','-qtt','-S','/export/home/user/.libnet-openssh-per
+l/user-mylinux-19767-362270','-l','user','mylinux0.qa.comp','--','ls 
+-l gLogs/*.log']
# open_ex: ['ssh','-qtt','-S','/export/home/user/.libnet-openssh-perl/
+user-mylinux-19767-362270','-l','user','mylinux0.qa.comp','--','ls -l
+ gLogs/*.log']
# io3 mloop, cin: 0, cout: 1, cerr: 1
# io3 fast, cin: 0, cout: 1, cerr: 1
# stdout, bytes read: 93 at offset 0
#> 2d 72 77 2d 72 2d 2d 72 2d 2d 20 31 20 66 6d 73 61 64 6d 36 30 20 6
+6 6d 73 20 31 30 35 30 32 20 | -rw-r--r-- 1 user usergrp 10502
#> 4a 75 6e 20 32 34 20 31 36 3a 32 37 20 2f 77 6f 72 6b 31 2f 64 36 2
+f 62 75 69 6c 64 73 2f 44 41 | Jun 24 16:27
#> 54 41 46 49 58 45 53 2f 4c 6f 67 73 2f 64 71 6c 5f 6f 75 74 70 75 7
+4 2e 6c 6f 67 0d 0a          | /Logs/output.log..
# io3 fast, cin: 0, cout: 1, cerr: 1
# stdout, bytes read: 0 at offset 93
# stderr, bytes read: 0
# leaving _io3()
# _waitpid(19780) => pid: 19780, rc:
# DESTROY(Net::OpenSSH=HASH(0x285b710), pid: 19768)
# killing master
# sending exit control to master
# call args: ['ssh','-O','exit','-T','-S','/export/home/user/.libnet-o
+penssh-perl/user-mylinux-19767-463633','-l','user','mylinux0.qa.comp'
+,'--']
# open_ex: ['ssh','-O','exit','-T','-S','/export/home/user/.libnet-ope
+nssh-perl/user-mylinux-19767-463633','-l','user','mylinux0.qa.comp','
+--']
-rw-r--r-- 1 user usergrp 10502 Jun 24 16:27 Logs/output.log

# io3 mloop, cin: 0, cout: 1, cerr: 0
# io3 fast, cin: 0, cout: 1, cerr: 0
# stdout, bytes read: 20 at offset 0
#> 45 78 69 74 20 72 65 71 75 65 73 74 20 73 65 6e 74 2e 0d 0a        
+                             | Exit request sent...
# io3 fast, cin: 0, cout: 1, cerr: 0
# stdout, bytes read: 0 at offset 20
# leaving _io3()
# _waitpid(19781) => pid: 19781, rc:
# _kill_master: 19768
# waitpid(master: 19768) => pid: 0, rc:
# waitpid(master: 19768) => pid: 19768, rc: Interrupted system call
Killed by signal 1.
# DESTROY(Net::OpenSSH=HASH(0x285c238), pid: 19777)
# killing master
# sending exit control to master
# set_error(1 - control command failed: master ssh connection broken)
# _kill_master: 19777
# waitpid(master: 19777) => pid: 0, rc: No such file or directory
# waitpid(master: 19777) => pid: 19777, rc: Interrupted system call
[download]

It seems you are not using the latest stable version of the module (0.62). Update it.

Also, include the full debugging output, not just an excerpt.

I tried with the 0.62 version and also got "Killed by signal 1.". Noticed that if a single command for system, capture or capture2, I don't get the error. But will get error when I run $ssh->system({tty=>1},@cmd) more than one time against same host. "Killed by signal 1." will happen on the last $ssh->system(@cmd) or capture(@cmd) or capture2(@cmd)