IllegalArgumentException: The validated expression is false #2344

Hello,

I created a proof build configuration that does a checkout of a project and builds it. However, right after the checkout, it fails due to an error: "Error executing grid job caused by: The validated expression is false"

I'm not sure why it fails but I tried it 3 times in a row and it always fails at the same place. Here is the complete stacktrace:

17:16:36,340 DEBUG - Performing status on external item at 'src\externals\libpif\android':
17:16:33,305 INFO  - Executing post-execute action...
17:16:33,306 ERROR - Step 'master>Checkout' is failed.
    java.lang.RuntimeException: Error executing grid job
        at com.pmease.quickbuild.grid.GridTaskFuture.get(GridTaskFuture.java:68)
        at com.pmease.quickbuild.grid.GridTaskFuture.get(GridTaskFuture.java:85)
        at com.pmease.quickbuild.plugin.basis.checkout.CheckoutStep.run(CheckoutStep.java:97)
        at com.pmease.quickbuild.plugin.basis.checkout.CheckoutStep$$EnhancerByCGLIB$$553127f3.CGLIB$run$0(<generated>)
        at com.pmease.quickbuild.plugin.basis.checkout.CheckoutStep$$EnhancerByCGLIB$$553127f3$$FastClassByCGLIB$$189dc910.invoke(<generated>)
        at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:215)
        at com.pmease.quickbuild.DefaultScriptEngine$Interpolator.intercept(DefaultScriptEngine.java:269)
        at com.pmease.quickbuild.plugin.basis.checkout.CheckoutStep$$EnhancerByCGLIB$$553127f3.run(<generated>)
        at com.pmease.quickbuild.stepsupport.Step.execute(Step.java:501)
        at com.pmease.quickbuild.stepsupport.StepExecutionJob.executeStepAwareJob(StepExecutionJob.java:30)
        at com.pmease.quickbuild.stepsupport.StepAwareJob.executeBuildAwareJob(StepAwareJob.java:47)
        at com.pmease.quickbuild.BuildAwareJob.execute(BuildAwareJob.java:61)
        at com.pmease.quickbuild.grid.GridJob.run(GridJob.java:78)
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
        at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
    Caused by: java.lang.IllegalArgumentException: The validated expression is false
        at org.apache.commons.lang.Validate.isTrue(Validate.java:181)
        at com.pmease.quickbuild.plugin.scm.svn.SvnProofBuildSupport.getLocalChange(SvnProofBuildSupport.java:333)
        at com.pmease.quickbuild.plugin.scm.svn.SvnProofBuildSupport$$EnhancerByCGLIB$$ab8d53ab.CGLIB$getLocalChange$5(<generated>)
        at com.pmease.quickbuild.plugin.scm.svn.SvnProofBuildSupport$$EnhancerByCGLIB$$ab8d53ab$$FastClassByCGLIB$$bb9ddde0.invoke(<generated>)
        at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:215)
        at com.pmease.quickbuild.DefaultScriptEngine$Interpolator.intercept(DefaultScriptEngine.java:269)
        at com.pmease.quickbuild.plugin.scm.svn.SvnProofBuildSupport$$EnhancerByCGLIB$$ab8d53ab.getLocalChange(<generated>)
        at com.pmease.quickbuild.plugin.basis.checkout.LocalChangeCollectJob.executeStepAwareJob(LocalChangeCollectJob.java:60)
        ... 9 more
17:16:33,427 INFO  - Checking step execute condition...
17:16:33,428 INFO  - Step execute condition not satisfied, step will be skipped.
17:16:33,465 INFO  - Executing post-execute action...
17:16:33,466 ERROR - Step 'master' is failed: Composite step 'master' failed due to unsatisfication of success condition.

Do you have any idea why? I have another configuration that is very similar to this one (except it does not have proof build enabled) and it manages to check out + build correctly.

I'm running QB 5.0.18.

Thanks.