Maven 3.1.0 breaks Google App Engine Maven Plugin

Question

Looks likes Google App Engine plugin is broken with new maven 3.1.0 release. When I am trying to run development server, I am getting exception

Caused by: java.lang.ClassNotFoundException: org.sonatype.aether.RepositorySystem
        at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
        ... 57 more
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

My maven version is

Apache Maven 3.1.0 (893ca28a1da9d5f51ac03827af98bb730128f9f2; 2013-06-28 05:15:32+0300)
Maven home: C:\Program Files\Maven\apache-maven-3.1.0
Java version: 1.7.0_25, vendor: Oracle Corporation
Java home: C:\Program Files\Java\jdk1.7.0_25\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"

There is a conluence page about this problem on Apache site http://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound

Answer 1

If you need to use the plug-in with Maven 3.1.0 then you can use the latest 1.8.3-SNAPSHOT version (from the Sonatype repository, see below) which has this problem fixed.

<plugin>
  <groupId>com.google.appengine</groupId>
  <artifactId>appengine-maven-plugin</artifactId>
  <version>1.8.3-SNAPSHOT</version>
</plugin>

<pluginRepository>
  <id>sonatype-nexus-snapshots</id>
  <name>Sonatype Nexus Snapshots</name>
  <url>https://oss.sonatype.org/content/repositories/google-snapshots/</url>
</pluginRepository>

Answer 2

See also this question:

Move to version 3.8.0 of the android-maven-plugin, it solves the issue.

Answer 3

I had the same problem, but moving back to Maven 3.0.5 solved the problem