Update to a newer version of the exec-maven-plugin to get rid of killAfter warnings.

juliac/pom.xml

@@ -152,7 +152,7 @@
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>exec-maven-plugin</artifactId>
-                    <version>1.3.2</version>
+                    <version>1.6.0</version>
                 </plugin>
             </plugins>
         </pluginManagement>