How to setup Maven home in IntelliJ ?

http://devnet.jetbrains.net/thread/278634

A valid Maven installation should contain bin/m2.conf

$ sudo find / -name m2.conf

/home/david/.hudson/maven/slavebundle/bundled-maven/bin/m2.conf

/home/david/tools/springsource/maven-2.2.1.RELEASE/bin/m2.conf

/usr/share/maven2/bin/m2.conf

/etc/maven2/m2.conf

$ export M2_HOME=/usr/share/maven