Huh? It sounds like you are talking about maven so I guess you are refering to the ui build.
Can't be. Here are the steps I followed.
1. Check out the sources (per http://wiki.jboss.org/wiki/Wiki.jsp?page=SeamRepository)
cvs -d:pserver:firstname.lastname@example.org:/cvsroot/jboss co jboss-seam
2. Build them (per release-process.txt)
$ ant cleanall dist
[zip] Building zip: c:\oss\jboss-seam-2.0.0.BETA1.zip
[tar] Building tar: c:\oss\jboss-seam-2.0.0.BETA1.tar.gz
Total time: 5 minutes 36 seconds
The binaries are in the parent directory of the sources.