Hi,
The simplest way to build Seam Tools via maven is to do the following steps:
1) cd <trunk_folder>
2) mvn clean install -f build/parent/pom.xml -P helios-no-target
3) mvn clean install -f build/pom.xml -Dmaven.test.skip -P helios-no-target,seam-bootstrap
Make sure you are using Maven 3 !