Based on the input provided to ParentFolder/pom.xml, either Module1 or Module2 should be checked out first from the SVN and then build should be performed.
However, Maven looks for existence of module's pom.xml before checkout goal of ParentFolder/pom.xml gets executed. Due to this build is failing evern before checkout.
Generally, you don;t use maven to check out the source. Maven works after you have used other tools to checkout the saource
Sure, you can finagle it to check out the source and then build that source. However, there are much easier ways to do the same thing. Just use the svn command line utility