feat: improve exception handling and debug experience

Author: manusa

it/src/test/java/org/eclipse/jkube/integrationtests/assertions/InvocationResultAssertion.java

@@ -14,6 +14,9 @@
 package org.eclipse.jkube.integrationtests.assertions;
 
 import org.apache.maven.shared.invoker.InvocationResult;
+import org.eclipse.jkube.integrationtests.maven.MavenInvocationResult;
+
+import java.util.Arrays;
 
 public class InvocationResultAssertion {
 
@@ -26,6 +29,10 @@ public static void assertInvocation(InvocationResult invocationResult) {
       if (invocationResult.getExecutionException() != null) {
         message.append("\n").append(invocationResult.getExecutionException().getMessage());
       }
+      if (invocationResult instanceof MavenInvocationResult){
+        Arrays.stream(((MavenInvocationResult) invocationResult).getStdOut().split("\r?\n"))
+          .forEach(line -> message.append("\n  > ").append(line));
+      }
       throw new AssertionError(message.toString());
     }
   }