cvs -d :pserver:anonymous@cvs.devel.redhat.com:/cvs/dist co jbossas
cd jbossas/RHEL-4-EP-5-JDK6/
make sources
cd ~/JBPAPP_5_0_0_GA
unzip -q /path/to/jbossas-5.0.0-tp-full.zip
cd build; ./build.sh

I had to remove jrockit-pluggable-instrumentor and add jboss-ejb3-metrics-deployer in pom.xml (as it is in the original pom.xml) otherwise I ended up with a build error:

Searching for build.xml ...
Buildfile: /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/build/build.xml

maven-init:
[echo] Maven Home set to /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/tools/maven

maven-install:
[java] [INFO] Scanning for projects...
[java] Downloading: http://repository.jboss.org/maven2-brew/org/jboss/jboss-parent/4/jboss-parent-4.pom
[java] Downloading: http://repository.jboss.org/maven2/org/jboss/jboss-parent/4/jboss-parent-4.pom
[java] 10K downloaded
[java] [INFO] ------------------------------------------------------------------------
[java] [ERROR] FATAL ERROR
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Error building POM (may not be this project's POM).
[java]
[java]
[java] Project ID: org.jboss.jbossas:jboss-as-thirdparty
[java] POM Location: /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] Validation Messages:
[java]
[java] [0] 'dependencies.dependency.version' is missing for org.jboss.aop:jrockit-pluggable-instrumentor
[java]
[java]
[java] Reason: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java]
[java]
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Trace
[java] org.apache.maven.reactor.MavenExecutionException: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:378)
[java] at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:292)
[java] at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:129)
[java] at org.apache.maven.cli.MavenCli.main(MavenCli.java:287)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:597)
[java] at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
[java] at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
[java] at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
[java] at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
[java] Caused by: org.apache.maven.project.InvalidProjectModelException: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.processProjectLogic(DefaultMavenProjectBuilder.java:1108)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.buildInternal(DefaultMavenProjectBuilder.java:878)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.buildFromSourceFileInternal(DefaultMavenProjectBuilder.java:506)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.build(DefaultMavenProjectBuilder.java:198)
[java] at org.apache.maven.DefaultMaven.getProject(DefaultMaven.java:583)
[java] at org.apache.maven.DefaultMaven.collectProjects(DefaultMaven.java:461)
[java] at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:365)
[java] ... 11 more
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Total time: 5 seconds
[java] [INFO] Finished at: Fri Oct 30 13:53:11 CET 2009
[java] [INFO] Final Memory: 1M/6M
[java] [INFO] ------------------------------------------------------------------------
[java] Java Result: 1
[java] [INFO] Scanning for projects...
[java] [INFO] ------------------------------------------------------------------------
[java] [ERROR] FATAL ERROR
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Error building POM (may not be this project's POM).
[java]
[java]
[java] Project ID: org.jboss.jbossas:jboss-as-thirdparty
[java] POM Location: /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] Validation Messages:
[java]
[java] [0] 'dependencies.dependency.version' is missing for org.jboss.aop:jrockit-pluggable-instrumentor
[java]
[java]
[java] Reason: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java]
[java]
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Trace
[java] org.apache.maven.reactor.MavenExecutionException: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:378)
[java] at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:292)
[java] at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:129)
[java] at org.apache.maven.cli.MavenCli.main(MavenCli.java:287)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[java] at java.lang.reflect.Method.invoke(Method.java:597)
[java] at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
[java] at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
[java] at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
[java] at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
[java] Caused by: org.apache.maven.project.InvalidProjectModelException: Failed to validate POM for project org.jboss.jbossas:jboss-as-thirdparty at /home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/thirdparty/pom.xml
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.processProjectLogic(DefaultMavenProjectBuilder.java:1108)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.buildInternal(DefaultMavenProjectBuilder.java:878)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.buildFromSourceFileInternal(DefaultMavenProjectBuilder.java:506)
[java] at org.apache.maven.project.DefaultMavenProjectBuilder.build(DefaultMavenProjectBuilder.java:198)
[java] at org.apache.maven.DefaultMaven.getProject(DefaultMaven.java:583)
[java] at org.apache.maven.DefaultMaven.collectProjects(DefaultMaven.java:461)
[java] at org.apache.maven.DefaultMaven.collectProjects(DefaultMaven.java:534)
[java] at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:365)
[java] ... 11 more
[java] [INFO] ------------------------------------------------------------------------
[java] [INFO] Total time: 2 seconds
[java] [INFO] Finished at: Fri Oct 30 13:53:14 CET 2009
[java] [INFO] Final Memory: 2M/8M
[java] [INFO] ------------------------------------------------------------------------
[java] Java Result: 1

BUILD FAILED
/home/jarek/Desktop/svn/JBPAPP_5_0_0_GA/build/build.xml:1203: Unable to build maven modules. See maven output for details.

Total time: 9 seconds