external libraries missing maven dependency jar

when i clone maven-plugin from 'https://github.com/jenkinsci/maven-plugin.git' and use idea to import this project by pom.xml.

the project's dependency libraries managed by maven is missing from the 'External Libraries'

i searched and found some suggesting like:

• Close your project window (and IntelliJ) and remove all

  *.iml

  files and all

  .idea

  folders (there should be one per module)
• Run

  mvn clean install

  from the command line
• Re-import the project into IntelliJ and pay attention when it asks you to enable auto-import

But it doesn't work.

Anybody knows why and how to fix this problem?

By the way, my own projects is correct.