java.lang.NullPointerException
	at hudson.model.Slave.createLauncher(Slave.java:420)
	at org.jenkinsci.plugins.oneshot.OneShotSlave.createLauncher(OneShotSlave.java:264)
	at org.jenkinsci.plugins.workflow.support.DefaultStepContext.makeLauncher(DefaultStepContext.java:112)
	at org.jenkinsci.plugins.workflow.support.DefaultStepContext.get(DefaultStepContext.java:68)
	at org.jenkinsci.plugins.workflow.steps.StepDescriptor.checkContextAvailability(StepDescriptor.java:251)
	at org.jenkinsci.plugins.workflow.cps.DSL.invokeStep(DSL.java:179)
	at org.jenkinsci.plugins.workflow.cps.DSL.invokeMethod(DSL.java:126)
	at org.jenkinsci.plugins.workflow.cps.CpsScript.invokeMethod(CpsScript.java:108)
	at groovy.lang.GroovyObject$invokeMethod.call(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
	at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:151)
	at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:21)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:115)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:103)
	at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:149)
	at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:146)
	at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.methodCall(SandboxInvoker.java:16)
	at WorkflowScript.backupWorkspace(WorkflowScript:46)
	at WorkflowScript.scenario(WorkflowScript:180)
	at ___cps.transform___(Native Method)
	at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:57)
	at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:109)
	at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:82)
	at sun.reflect.GeneratedMethodAccessor271.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
	at com.cloudbees.groovy.cps.impl.ClosureBlock.eval(ClosureBlock.java:46)
	at com.cloudbees.groovy.cps.Next.step(Next.java:58)
	at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:154)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:33)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:108)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:163)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:324)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$100(CpsThreadGroup.java:78)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:236)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:224)
	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:63)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
	Suppressed: java.lang.NullPointerException
		at hudson.model.Slave.createLauncher(Slave.java:420)
		at org.jenkinsci.plugins.oneshot.OneShotSlave.createLauncher(OneShotSlave.java:264)
		at org.jenkinsci.plugins.workflow.support.DefaultStepContext.makeLauncher(DefaultStepContext.java:112)
		at org.jenkinsci.plugins.workflow.support.DefaultStepContext.get(DefaultStepContext.java:68)
		at org.jenkinsci.plugins.credentialsbinding.impl.BindingStep$Callback.finished(BindingStep.java:182)
		at org.jenkinsci.plugins.workflow.steps.BodyExecutionCallback$TailCall.onFailure(BodyExecutionCallback.java:124)
		at org.jenkinsci.plugins.workflow.cps.CpsBodyExecution$FailureAdapter.receive(CpsBodyExecution.java:343)
		at com.cloudbees.groovy.cps.impl.ThrowBlock$1.receive(ThrowBlock.java:68)
		at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
		... 21 more