Using /devstudio-trunk/releng/org.jboss.ide.eclipse.releng/hudson/build.sh with the following parameters changed, JMX will build on its own:

builders=jmx
nightlyBuildSteps=standalone.product,reports,build-results,update-site

Turning tests back on, however, the build fails:

builders=jmx
nightlyBuildSteps=standalone.product,reports,tests,build-results,update-site

[java] Java Result: 13
[echo]
[echo] The builder <b>tests</b> failed to compile with the following results:<br/><br/>
[echo]
[echo] <pre>
[echo] BUILD FAILED
[echo] /opt/public/jbt-jbds/nightly-with-tests/jbds-build/clean-eclipse/eclipse/plugins/org.eclipse.pde.build_3.4.1.R34x_v20080805/scripts/build.xml:24: The following error occurred while executing this line:
[echo] /opt/public/jbt-jbds/nightly-with-tests/jbds-build/clean-eclipse/eclipse/plugins/org.eclipse.pde.build_3.4.1.R34x_v20080805/scripts/build.xml:64: The following error occurred while executing this line:
[echo] /opt/public/jbt-jbds/nightly-with-tests/org.jboss.ide.eclipse.releng/builders/tests/customTargets.xml:13: The following error occurred while executing this line:
[echo] /opt/public/jbt-jbds/nightly-with-tests/jbds-build/clean-eclipse/eclipse/plugins/org.eclipse.pde.build_3.4.1.R34x_v20080805/scripts/genericTargets.xml:88: Bundle org.jboss.tools.common.kb.test_0.0.0 failed to resolve.:
[echo] Missing required plug-in org.jboss.tools.common_0.0.0.
[echo] Missing required plug-in org.jboss.tools.common.kb_0.0.0.
[echo] Missing required plug-in org.jboss.tools.common.test_0.0.0.
[echo] Missing required plug-in org.jboss.tools.common.projecttemplates_0.0.0.
[echo]
[echo]
[echo] Total time: 3 minutes 2 seconds
[echo] </pre>
[echo] /opt/public/jbt-jbds/nightly-with-tests/jbds-build/3.0.0.CR1/200811132054/tests

BUILD FAILED
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/buildNightly.xml:12: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/build.xml:56: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/build.xml:27: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/build.xml:37: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/product/productBuild.xml:76: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/product/productBuild.xml:105: The following error occurred while executing this line:
/home/nboldt/eclipse/workspace-jboss/devstudio-trunk/releng/org.jboss.ide.eclipse.releng/builders/product/productBuild.xml:261: Specify at least one source - a file or a resource collection.

Total time: 23 minutes 21 seconds

I suspect this is a result of the tests being coupled together, such that they depend on the whole build (builders=jmx,examples,drools-ide,archives,richfaces,jbpm-convert,freemarker,hibernate-tools,struts,jbpm,as,seam,esb,ws,birt,portlet,smooks) and its output.

Would there be value in incrementally splitting each build's tests out so they can run independently? eg.,

builders=jmx,jmx-tests
nightlyBuildSteps=standalone.product,reports,tests-jmx,build-results,update-site