People on the forums were having trouble building from trunk. See http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4251450#4251450

For the record, here's the process that I just followed. First, I set up my environment per the Reference Guide (http://www.jboss.org/file-access/default/members/dna/freezone/docs/0.5/manuals/reference/html/development-tools.html). I then made sure to remove my local Maven repository (something that most people don't have to do, but it allows me to simulate someone starting fresh):

$ rm -rf ~/.m2/repository

Then I checked out the latest from trunk:
$ svn checkout http://anonsvn.jboss.org/repos/dna/trunk/
$ cd trunk

Just to be clear of the version information I'm running:
$ mvn -version
Maven version: 2.0.9
Java version: 1.5.0_19
OS name: "mac os x" version: "10.5.8" arch: "i386" Family: "unix"
$ echo $MAVEN_OPTS
-Xmx256m

Note the Maven version. Obviously I'm running on a Mac, but we have active contributors on Linux and Windows. I then ran the build (without integration tests):
$ mvn clean install

After about 10 minutes (with a lot of Maven downloads), this build should have completed, but did result in an error in the Java sequencer project, which apparently depends on 'dna-integration-test'. Here's the error:

[INFO] ------------------------------------------------------------------------
[INFO] Building JBoss DNA Java Sequencer
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
...
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to resolve artifact.

Missing:
----------
1) org.jboss.dna:dna-integration-tests:jar:0.6-SNAPSHOT

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.jboss.dna -DartifactId=dna-integration-tests -Dversion=0.6-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=org.jboss.dna -DartifactId=dna-integration-tests -Dversion=0.6-SNAPSHOT -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id]

Path to dependency:
1) org.jboss.dna:dna-sequencer-java:jar:0.6-SNAPSHOT
2) org.jboss.dna:dna-integration-tests:jar:0.6-SNAPSHOT

----------
1 required artifact is missing.

for artifact:
org.jboss.dna:dna-sequencer-java:jar:0.6-SNAPSHOT

from the specified remote repositories:
central (http://repo1.maven.org/maven2),
repository.jboss.org (http://repository.jboss.org/maven2),
apiviz.release (http://apiviz.googlecode.com/svn/site/repo/mvn/release),
jboss-snapshot (http://snapshots.jboss.org/maven2),
snapshots.jboss.org (http://snapshots.jboss.org/maven2),
jboss (http://repository.jboss.com/maven2)