The plugin is incompatible with Maven-3.1.0

[GoogleCodeExporter]

The app engine maven plugin doesn't work with Maven-3.1.0.

Maven-3.1.0 release note[1] says:

But this is a significant change and is likely to cause issues in any plugin 
that depends on the now deprecated Sonatype Aether.

Probably we should contact maven guys to update this list[2].

1: http://maven.apache.org/docs/3.1.0/release-notes.html
2: https://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound

Original issue reported on code.google.com by tmat...@google.com on 15 Jul 2013 at 11:51

[GoogleCodeExporter]

A command like appengine:devserver or appengine:update causes an error as 
follows:
Caused by: java.lang.NoClassDefFoundError: 
Lorg/sonatype/aether/RepositorySystem;

The original report is here:
https://groups.google.com/d/msg/google-appengine/FgZrGAJr0T8/VaEXYgPUX7cJ

Original comment by tmat...@google.com on 16 Jul 2013 at 12:08

[GoogleCodeExporter]

It looks like Aether was moved to be a toplevel eclipse project instead of a 
sonatype project.  Should be an easy fix, but users might get some weird errors 
for a bit...

Original comment by matts...@google.com on 16 Jul 2013 at 12:32

• Changed state: Accepted

[GoogleCodeExporter]

Would is be possible to have 1 single plugin to work with both releases?

Original comment by ludovic....@gmail.com on 16 Jul 2013 at 12:53

[GoogleCodeExporter]

Nope, I've managed to get it working in 3.1.0 only.  The plugin will now 
require maven 3.1.0.

Original comment by matts...@google.com on 18 Jul 2013 at 12:21

[GoogleCodeExporter]

This will be for 1.8.3-SNAPSHOT for now, I'm not sure when to pull it up to a 
non-snapshot release.

Original comment by matts...@google.com on 18 Jul 2013 at 12:25

[GoogleCodeExporter]

This is now scheduled for 1.8.3 and pushed to the repo and a snapshot is now 
available.

Original comment by matts...@google.com on 20 Jul 2013 at 12:58

• Changed state: Fixed

[GoogleCodeExporter]

change the pom like this and bingo:
...
...
...
<properties>
        <appengine.app.version>1</appengine.app.version>
        <appengine.target.version>1.9.9</appengine.target.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

...
...
...
 <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <version>3.1</version>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
...
...
...

"we can say it's maven pb but like this ; the app guestbook is ranning "
my mvn -v is 3.1.1
good luck

Original comment by kerbiche on 10 Sep 2014 at 2:07