JBDS update site fails to generate p2 metadata - only 3 components' features found!

Found this tonight – definitely a blocker for Beta1 since no one will be able to upgrade from JBDS 4.0.0.M1 to 4.0.0.M2 using this site [1].

JBDS update site only contains metadata for the three projects aggregated into it w/ b3aggr: Teiid, Drools, jBPM3.

Reason for this is a complete failure - hitherto undetected - to generate metadata:

p2:
[echo] Run p2.publisher.UpdateSitePublisher using launcherjar = /mnt/hudson_workspace/workspace/devstudio-nightly-4.0.0.M2/jbds-build/clean-eclipse/eclipse/plugins/org.eclipse.equinox.launcher_1.1.0.v20100507.jar
[p2] Generating metadata for ..
[p2] Status ERROR: org.eclipse.equinox.p2.artifact.repository code=0 java.lang.IllegalArgumentException
[p2] org.eclipse.equinox.launcher.Main
[p2] -metadataRepository
[p2] file:/mnt/hudson_workspace/workspace/devstudio-nightly-4.0.0.M2/jbds-build/site/eclipse/
[p2] -metadataRepositoryName
[p2] JBoss Developer Studio Stable Release Update Site
[p2] -artifactRepository
[p2] file:/mnt/hudson_workspace/workspace/devstudio-nightly-4.0.0.M2/jbds-build/site/eclipse/
[p2] -artifactRepositoryName
[p2] JBoss Developer Studio Stable Release Artifacts
[p2] -source
[p2] /mnt/hudson_workspace/workspace/devstudio-nightly-4.0.0.M2/jbds-build/site/eclipse/
[p2] -compress
[p2] -publishArtifacts
[p2] -reusePack200Files
[p2] -configs
[p2] ,,*
[p2] Java Result: 1

[1] http://reports.qa.atl.jboss.com/binaries/RHDS/updates/nightly/4.0.0.M2/