title: Maven 3.3.1 Config Error in IntelliJ Idea 14
body: <p>I got the maven .tar file from <a href="http://maven.apache.org/download.cgi">http://maven.apache.org/download.cgi</a>, and installed it to the path /usr/local/. I run the mvn -version command in the new window, the output is correct. Below is my .bash_profile in my home directory:  </p>
  
  <pre><code>JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk7/Contents/Home  
  CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar  
  PATH=$JAVA_HOME/bin:$PATH:  
  export JAVA_HOME  
  export CLASSPATH  
  export PATH  
  M2_HOME=/usr/local/maven  
  M2=$M2_HOME/bin  
  PATH=$M2:$PATH  
  export M2_HOME    
  export M2  
  export PATH
  </code></pre>
  
  <p>and the mvn -version is below :  </p>
  
  <pre><code>BianFranks-MacBook-Pro:~ Frank$ mvn -version  
  Apache Maven 3.3.1 (cab6659f9874fa96462afef40fcf6bc033d58c1c; 2015-03-    14T04:10:27+08:00)  
  Maven home: /usr/local/maven  
  Java version: 1.7.0_72, vendor: Oracle Corporation  
  Java home: /Library/Java/JavaVirtualMachines/jdk7/Contents/Home/jre  
  Default locale: en_US, platform encoding: UTF-8  
  OS name: "mac os x", version: "10.10.2", arch: "x86_64", family: "mac"
  </code></pre>
  
  <p>But the tips occurred when cleaning the module via Maven in Intellij IDEA 14:  </p>
  
  <pre><code>/Library/Java/JavaVirtualMachines/jdk7/Contents/Home/bin/java -Dmaven.home=/usr/local/maven -Dclassworlds.conf=/usr/local/maven/bin/m2.conf -Didea.launcher.port=7532 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA 14.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/usr/local/maven/boot/plexus-classworlds-2.5.2.jar:/Applications/IntelliJ IDEA 14.app/Contents/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain org.codehaus.classworlds.Launcher -Didea.version=14.0.2 clean  
  -Dmaven.multiModuleProjectDirectory system propery is not set. Check   $M2_HOME environment variable and mvn script match.   
  Process finished with exit code 1
  </code></pre>
  
  <p>the system property is not set, but I don't know how to set it...</p>