When we try to stop a running build on an AIX Unix, the following exception is thrown: {noformat}
10:21:24,480 ERROR - ***buildagent/framework/configuration/org.eclipse.osgi/com/pmease/quickbuild/execution/kill-tree.sh: pgrep: not found.
10:21:24,480 ERROR - ***/buildagent/framework/configuration/org.eclipse.osgi/com/pmease/quickbuild/execution/kill-tree.sh[14]: kill: 0403-008 The number of parameters specified is not correct.
10:21:24,588 ERROR - Error terminating process tree.
    com.pmease.quickbuild.QuickbuildException: Failed to run command: sh ***/buildagent/framework/configuration/org.eclipse.osgi/com/pmease/quickbuild/execution/kill-tree.sh 14942218
    Command return code: 1
    Command error output: ***/buildagent/framework/configuration/org.eclipse.osgi/com/pmease/quickbuild/execution/kill-tree.sh: pgrep: not found.
    ***/buildagent/framework/configuration/org.eclipse.osgi/com/pmease/quickbuild/execution/kill-tree.sh[14]: kill: 0403-008 The number of parameters specified is not correct.
        at com.pmease.quickbuild.execution.Commandline$ExecuteResult.buildException(Commandline.java:489)
        at com.pmease.quickbuild.execution.Commandline$ExecuteResult.checkReturnCode(Commandline.java:504)
        at com.pmease.quickbuild.execution.killtree.ProcessTree$1$1.killRecursively(ProcessTree.java:302)
        at com.pmease.quickbuild.execution.killtree.ProcessTree.killAll(ProcessTree.java:144)
        at com.pmease.quickbuild.execution.Commandline.terminateProcessTree(Commandline.java:404)
        at com.pmease.quickbuild.execution.Commandline.execute(Commandline.java:363)
        at com.pmease.quickbuild.execution.Commandline.execute(Commandline.java:222)
        at com.pmease.quickbuild.plugin.builder.ant.AntBuildStep.run(AntBuildStep.java:288)
        at com.pmease.quickbuild.plugin.builder.ant.AntBuildStep$$EnhancerByCGLIB$$9f9bd6b5.CGLIB$run$13(<generated>)
        at com.pmease.quickbuild.plugin.builder.ant.AntBuildStep$$EnhancerByCGLIB$$9f9bd6b5$$FastClassByCGLIB$$e4f62030.invoke(<generated>)
        at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:215)
        at com.pmease.quickbuild.DefaultScriptEngine$Interpolator.intercept(DefaultScriptEngine.java:273)
        at com.pmease.quickbuild.plugin.builder.ant.AntBuildStep$$EnhancerByCGLIB$$9f9bd6b5.run(<generated>)
        at com.pmease.quickbuild.stepsupport.Step.execute(Step.java:539)
        at com.pmease.quickbuild.stepsupport.StepExecutionJob.executeStepAwareJob(StepExecutionJob.java:30)
        at com.pmease.quickbuild.stepsupport.StepAwareJob.executeBuildAwareJob(StepAwareJob.java:45)
        at com.pmease.quickbuild.BuildAwareJob.execute(BuildAwareJob.java:60)
        at com.pmease.quickbuild.grid.GridJob.run(GridJob.java:106)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:483)
        at java.util.concurrent.FutureTask.run(FutureTask.java:274)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1157)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:627)
        at java.lang.Thread.run(Thread.java:809)
{noformat}