Maven-gae-plugin 0.9.4: no version available for org.codehaus.plexus:plexus-archiver:jar— Help me explain the solution of the bug

Question

This bug was closed on github, https://github.com/maven-gae-plugin/maven-gae-plugin/issues/39 however i don't understand its fixing, and when i execute gae goal such as mvn gae:update it always gives me the same problem. could anyone explain the root cause of this problem based on its fixing?

For your info, i copy-paste the original problem and its fixing here:

From this morning I continue to get this error:

Failed to execute goal net.kindleit:maven-gae-plugin:0.9.4:unpack (execution2) on project gui: Execution execution2 of goal net.kindleit:maven-gae-plugin:0.9.4:unpack failed: Plugin net.kindleit:maven-gae-plugin:0.9.4 or one of its dependencies could not be resolved: Failed to collect dependencies for net.kindleit:maven-gae-plugin:jar:0.9.4 (): No versions available for org.codehaus.plexus:plexus-archiver:jar:[1.2,3.0) within specified range

.. and I am stuck with this plugin at the moment!

the fix is:

.. and I added the "-U" option to the command I use to use: mvn clean verify .. it becomes: mvn -U clean verify

Thanks in advance.

Answer 1

If it can help someone, here is my solution for the error "No versions available for org.codehaus.plexus:plexus-archiver:jar:[1.2,3.0)".

I changed the pom configuration for gae-plugin :

<plugin>
    <groupId>net.kindleit</groupId>
    <artifactId>maven-gae-plugin</artifactId>
    <version>0.9.4</version>
    <dependencies>
        <dependency>
            <groupId>org.codehaus.plexus</groupId>
            <artifactId>plexus-archiver</artifactId>
            <version>2.1.2</version>
        </dependency>
    </dependencies>
</plugin>

Answer 2

The GAE runtime provided in Maven repos always lags behind official SDK. At the moment official SDK is 1.7.1, but GAE runtime is only at 1.7.0. That's why your unpack command fails - it can't find the version of runtime that you are requesting.