I am getting below error while building iOS app. Please suggest.  
.ipa file was created in last build but job was failed.

Job Error:-

Build Log:-
FATAL: command execution failed
java.io.EOFException
at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source)
at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown Source)
at java.io.ObjectInputStream.readStreamHeader(Unknown Source)
at java.io.ObjectInputStream.<init>(Unknown Source)
at hudson.remoting.ObjectInputStreamEx.<init>(ObjectInputStreamEx.java:48)
at hudson.remoting.AbstractSynchronousByteArrayCommandTransport.read(AbstractSynchronousByteArrayCommandTransport.java:34)
at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:59)
Caused: java.io.IOException: Unexpected termination of the channel
at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:73)
Caused: java.io.IOException: Backing channel 'MAC' is disconnected.
at hudson.remoting.RemoteInvocationHandler.channelOrFail(RemoteInvocationHandler.java:192)
at hudson.remoting.RemoteInvocationHandler.invoke(RemoteInvocationHandler.java:257)
at com.sun.proxy.$Proxy72.isAlive(Unknown Source)
at hudson.Launcher$RemoteLauncher$ProcImpl.isAlive(Launcher.java:1043)
at hudson.Launcher$RemoteLauncher$ProcImpl.join(Launcher.java:1035)
at hudson.tasks.CommandInterpreter.join(CommandInterpreter.java:155)
at hudson.tasks.CommandInterpreter.perform(CommandInterpreter.java:109)
at hudson.tasks.CommandInterpreter.perform(CommandInterpreter.java:66)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:735)
at hudson.model.Build$BuildExecution.build(Build.java:206)
at hudson.model.Build$BuildExecution.doRun(Build.java:163)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:490)
at hudson.model.Run.execute(Run.java:1735)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:97)
at hudson.model.Executor.run(Executor.java:405)
Build step 'Execute shell' marked build as failure
Finished: FAILURE
MAC Node Log:-

This is a Unix agent Evacuated stdout Agent successfully connected and online ERROR: Connection terminated java.io.EOFException at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source) at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown Source) at java.io.ObjectInputStream.readStreamHeader(Unknown Source) at java.io.ObjectInputStream.<init>(Unknown Source) at hudson.remoting.ObjectInputStreamEx.<init>(ObjectInputStreamEx.java:48) at hudson.remoting.AbstractSynchronousByteArrayCommandTransport.read(AbstractSynchronousByteArrayCommandTransport.java:34) at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:59) Caused: java.io.IOException: Unexpected termination of the channel at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:73) ERROR: Socket connection to SSH server was lost java.net.SocketTimeoutException: Read timed out at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(Unknown Source) at java.net.SocketInputStream.read(Unknown Source) at java.net.SocketInputStream.read(Unknown Source) at com.trilead.ssh2.crypto.cipher.CipherInputStream.fill_buffer(CipherInputStream.java:41) at com.trilead.ssh2.crypto.cipher.CipherInputStream.internal_read(CipherInputStream.java:52) at com.trilead.ssh2.crypto.cipher.CipherInputStream.getBlock(CipherInputStream.java:79) at com.trilead.ssh2.crypto.cipher.CipherInputStream.read(CipherInputStream.java:108) at com.trilead.ssh2.transport.TransportConnection.receiveMessage(TransportConnection.java:232) at com.trilead.ssh2.transport.TransportManager.receiveLoop(TransportManager.java:706) at com.trilead.ssh2.transport.TransportManager$1.run(TransportManager.java:502) at java.lang.Thread.run(Unknown Source) Slave JVM has not reported exit code before the socket was lost [11/24/17 08:48:30] [SSH] Connection closed. [11/24/17 08:48:56] [SSH] Opening SSH connection to ...:22. [11/24/17 08:48:58] [SSH] WARNING: SSH Host Keys are not being verified. Man-in-the-middle attacks may be possible against this connection. [11/24/17 08:48:59] [SSH] Authentication successful. [11/24/17 08:48:59] [SSH] The remote user's environment is: BASH=/bin/bash