$ atlas-debug

Executing: /usr/share/atlassian-plugin-sdk-4.2.20/apache-maven/bin/mvn com.atlassian.maven.plugins:maven-amps-dispatcher-plugin:4.2.20:debug -gs /usr/share/atlassian-plugin-sdk-4.2.20/apache-maven/conf/settings.xml
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Chegg Pre[Rcv|Merge] Shell Delegator
[INFO] task-segment: [com.atlassian.maven.plugins:maven-amps-dispatcher-plugin:4.2.20:debug]
[INFO] ------------------------------------------------------------------------
[INFO] Preparing amps-dispatcher:debug
[INFO] [stash:copy-bundled-dependencies]
[INFO] [dependency:unpack-dependencies]
[INFO] commons-lang-2.6.jar already exists in destination.
[INFO] gson-2.2.2-atlassian-1.jar already exists in destination.
[INFO] [stash:compress-resources]
[INFO] Compiling javascript using YUI
[INFO] Compressing XML files
[INFO] Nothing to do, /stash/plugins/atlastutorial/plugin-04-Pre-NoConfig/stashplugins/preReceive-PassParams/target/classes/atlassian-plugin.xml is younger than the original
[INFO] Nothing to do, /stash/plugins/atlastutorial/plugin-04-Pre-NoConfig/stashplugins/preReceive-PassParams/target/classes/logback.xml is younger than the original
[INFO] [resources:resources]
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 4 resources
[INFO] [stash:filter-plugin-descriptor]
[INFO] [resources:copy-resources

{execution: virtual-execution}

]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] [compiler:compile]
[INFO] Nothing to compile - all classes are up to date
[INFO] [stash:generate-manifest]
[INFO] No manifest instructions found, adding only non-OSGi manifest attributes
[INFO] [stash:generate-rest-docs]
[INFO] [resources:testResources]
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /stash/plugins/atlastutorial/plugin-04-Pre-NoConfig/stashplugins/preReceive-PassParams/src/test/resources
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Internal error in the plugin manager executing goal 'com.atlassian.maven.plugins:maven-amps-plugin:5.0-SNAPSHOT:filter-test-plugin-descriptor': Unable to load the mojo 'com.atlassian.maven.plugins:maven-amps-plugin:5.0-SNAPSHOT:filter-test-plugin-descriptor' in the plugin 'com.atlassian.maven.plugins:maven-amps-plugin'. A required class is missing: Lorg/apache/maven/plugin/BuildPluginManager;
org.apache.maven.plugin.BuildPluginManager
[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 23 seconds
[INFO] Finished at: Tue May 27 13:20:24 PDT 2014
[INFO] Final Memory: 71M/371M
[INFO] ------------------------------------------------------------------------

I have already tried the solutions given in [ AMPS-1112 & https://answers.atlassian.com/questions/277302/a-required-class-is-missing-lorg-apache-maven-plugin-buildpluginmanager ] and they dont work for my case.

Failed Solution 1
-----------------------
<plugin>
<groupId>com.atlassian.maven.plugins</groupId>
<artifactId>maven-amps-plugin</artifactId>
<version>${amps.version}</version>
<extensions>true</extensions>
</plugin>

Failed Solution 2
-----------------------
Copied the jar
Link for JAR file: https://drive.google.com/file/d/0B8HwtPHtTlJAcGhjVWZ1OFBfdUU/edit?usp=sharing>
Location in FileSystem: \.m2\repository\com\atlassian\maven\plugins\maven-amps-plugin\5.0-m1