Fail to copy with Jenkins (MDEP-187) - maven

Question

I'm using Jenkins to build the Jenkins code in the GitHub repository but I'm having a problem:
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Jenkins war 1.626
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.4.1:clean (default-clean) # jenkins-war ---
[INFO] Deleting C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target
[INFO]
[INFO] --- maven-enforcer-plugin:1.0.1:enforce (enforce-maven) # jenkins-war ---
[INFO]
[INFO] --- maven-enforcer-plugin:1.0.1:display-info (display-info) # jenkins-war ---
[INFO] Maven Version: 3.3.3
[INFO] JDK Version: 1.7.0_79 normalized as: 1.7.0-79
[INFO] OS Info: Arch: amd64 Family: windows Name: windows 8.1 Version: 6.3
[INFO]
[INFO] --- maven-enforcer-plugin:1.0.1:enforce (default) # jenkins-war ---
[INFO] Adding ignore: org.eclipse.jetty.spdy.*
[INFO]
[INFO] --- maven-enforcer-plugin:1.0.1:enforce (enforce-banned-dependencies) # jenkins-war ---
[INFO]
[INFO] --- build-helper-maven-plugin:1.7:timestamp-property (timestamp-property) # jenkins-war ---
[INFO] Setting property 'now' to '08/30/2015 18:58 GMT'.
[INFO]
[INFO] --- build-helper-maven-plugin:1.7:regex-property (version-property) # jenkins-war ---
[INFO] No match to regex '-SNAPSHOT' found in '1.626'.
[INFO] Setting property 'build.version' to '1.626'.
[INFO]
[INFO] --- build-helper-maven-plugin:1.7:add-source (add-source) # jenkins-war ---
[INFO] Source directory: C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target\generated-sources\localizer added.
[INFO]
[INFO] --- gmaven-plugin:1.5-jenkins-3:generateStubs (default) # jenkins-war ---
[INFO] No sources found for Java stub generation
[INFO]
[INFO] --- maven-dependency-plugin:2.8:list (list-dependencies) # jenkins-war ---
[INFO]
[INFO] --- maven-dependency-plugin:2.8:unpack-dependencies (executable-war-header) # jenkins-war ---
[INFO] Unpacking C:\.m2\repository\org\jenkins-ci\executable-war\1.30\executable-war-1.30.jar to C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target\jenkins with includes "**/*.class" and excludes ""
[INFO]
[INFO] --- maven-dependency-plugin:2.8:copy (resgen) # jenkins-war ---
[INFO] Configured Artifact: org.jenkins-ci.main:remoting:?:jar
[INFO] Configured Artifact: org.jenkins-ci.main:remoting:?:jar
[INFO] Configured Artifact: org.jenkins-ci.main:cli:jar-with-dependencies:?:jar
[INFO] Configured Artifact: org.jenkins-ci:winstone:?:jar
[INFO] Configured Artifact: org.jenkins-ci.main:maven-plugin:?:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:ssh-slaves:1.9:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:credentials:1.18:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:ssh-credentials:1.10:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:subversion:1.54:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:cvs:2.11:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:ant:1.2:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:javadoc:1.1:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:translation:1.10:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:external-monitor-job:1.4:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:ldap:1.11:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:pam-auth:1.1:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:mailer:1.11:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:matrix-auth:1.1:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:windows-slaves:1.0:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:antisamy-markup-formatter:1.1:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:matrix-project:1.4.1:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:script-security:1.13:hpi
[INFO] Configured Artifact: org.jenkins-ci.plugins:junit:1.2-beta-4:hpi
[INFO] Copying remoting-2.52.jar to C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target\jenkins\WEB-INF\remoting.jar
[INFO] Copying remoting-2.52.jar to C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target\jenkins\WEB-INF\slave.jar
[INFO] Copying classes to C:\Program Files (x86)\Jenkins\workspace\jenkins_scc12_test\war\target\jenkins\WEB-INF\jenkins-cli.jar
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Jenkins main module ................................ SUCCESS [ 2.497 s]
[INFO] Jenkins cli ........................................ SUCCESS [ 6.507 s]
[INFO] Jenkins core ....................................... SUCCESS [12:32 min]
[INFO] Jenkins war ........................................ FAILURE [ 10.954 s]
[INFO] Test harness for Jenkins and plugins ............... SKIPPED
[INFO] Jenkins plugin POM ................................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 12:55 min
[INFO] Finished at: 2015-08-31T02:58:30+08:00
[INFO] Final Memory: 179M/740M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-dependency-plugin:2.8:copy (resgen) on project jenkins-war: Artifact has not been packaged yet. When used on reactor artifact, copy should be executed after packaging: see MDEP-187. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR] mvn <goals> -rf :jenkins-war
Build step 'Invoke top-level Maven targets' marked build as failure
Recording test results
Finished: FAILURE
The code I'm using is of the last release: https://github.com/jenkinsci/jenkins/tree/8d8703a781f83be19086592e0c8fa4b4c14da13c
I'm using Maven to build.
I'm very new to this. Please help me to solve this problem.
JDK version: 1.7.0
Maven version: 3.3.3