After upgrading to 1.2.2 from 1.1, releases on projects created before the upgrade fail. The issue appears to be that the DefaultShellCommandHelper.createCommandline doesn't handle a null argument array. The initial cause is that the upgraded projects don't have the local repo set to anything, while newly created projects have it set to DEFAULT. I am attaching a patch that takes care of the null argument list, but perhaps an upgrade should bless projects with no default repo to use DEFAULT?

[ERROR] org.apache.maven.shared.release.ReleaseExecutionException
at org.apache.continuum.release.phase.AbstractContinuumRunGoalsPhase.execute(AbstractContinuumRunGoalsPhase.java:70)
at org.apache.continuum.release.phase.RunPrepareGoalsPhase.execute(RunPrepareGoalsPhase.java:47)
at org.apache.maven.shared.release.DefaultReleaseManager.prepare(DefaultReleaseManager.java:194)
at org.apache.maven.shared.release.DefaultReleaseManager.prepareWithResult(DefaultReleaseManager.java:107)
at org.apache.maven.continuum.release.executors.PrepareReleaseTaskExecutor.execute(PrepareReleaseTaskExecutor.java:43)
at org.apache.maven.continuum.release.executors.AbstractReleaseTaskExecutor.executeTask(AbstractReleaseTaskExecutor.java:67)
at org.codehaus.plexus.taskqueue.execution.ThreadedTaskQueueExecutor$ExecutorRunnable$1.run(ThreadedTaskQueueExecutor.java:116)
at edu.emory.mathcs.backport.java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:442)
at edu.emory.mathcs.backport.java.util.concurrent.FutureTask.run(FutureTask.java:178)
at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1061)
at edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:575)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
at org.apache.continuum.utils.shell.DefaultShellCommandHelper.createCommandline(DefaultShellCommandHelper.java:105)
at org.apache.continuum.utils.shell.DefaultShellCommandHelper.executeGoals(DefaultShellCommandHelper.java:176)
at org.apache.continuum.utils.shell.DefaultShellCommandHelper.executeGoals(DefaultShellCommandHelper.java:169)
at org.apache.continuum.release.phase.AbstractContinuumRunGoalsPhase.execute(AbstractContinuumRunGoalsPhase.java:62)
... 11 more