Problems using Oomph to setup Buildship dev environment

I’m trying to set up a dev environment to build and debug Buildship itself following these instructions but getting the error below from Oomph. (I am able to set up other Oomph-based products/projects so I suspect the problem is with the Buildship catalog entry, not with my environment.) Any suggestions?

Calculating requirements and dependencies.
Cannot complete the request.  Generating details.
ERROR: org.eclipse.equinox.p2.director code=10053 Cannot complete the install because one or more required items could not be found.
  at org.eclipse.oomph.util.OomphPlugin.coreException(OomphPlugin.java:291)
  at org.eclipse.oomph.p2.internal.core.ProfileTransactionImpl.resolve(ProfileTransactionImpl.java:428)
  at org.eclipse.oomph.p2.internal.core.ProfileTransactionImpl.commit(ProfileTransactionImpl.java:340)
  at org.eclipse.oomph.setup.p2.impl.P2TaskImpl.perform(P2TaskImpl.java:899)
  at org.eclipse.oomph.setup.internal.core.SetupTaskPerformer.doPerformNeededSetupTasks(SetupTaskPerformer.java:3828)
  at org.eclipse.oomph.setup.internal.core.SetupTaskPerformer.performNeededSetupTasks(SetupTaskPerformer.java:3756)
  at org.eclipse.oomph.setup.internal.core.SetupTaskPerformer.performTriggeredSetupTasks(SetupTaskPerformer.java:3737)
  at org.eclipse.oomph.setup.internal.core.SetupTaskPerformer.perform(SetupTaskPerformer.java:3630)
  at org.eclipse.oomph.setup.ui.wizards.ProgressPage$9.run(ProgressPage.java:593)
  at org.eclipse.oomph.setup.ui.wizards.ProgressPage$11$1.run(ProgressPage.java:720)
  at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)
  ERROR: org.eclipse.equinox.p2.director code=0 Software being installed: artificial_root 1.0.0.v1602012647639
  ERROR: org.eclipse.equinox.p2.director code=0 Missing requirement: artificial_root 1.0.0.v1602012647639 requires 'org.eclipse.equinox.p2.iu; org.codehaus.groovy24.feature.feature.group 0.0.0' but it could not be found

Thanks for the error report. I’ve fixed the oomph setup. The Eclipse installer will automatically pick up my changes. In case the sync hasn’t happened, you can manually load the setup file:

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Also note, that you can only select Eclipse 2020-09 on the main page. The groovy-eclipse plugin hasn’t added support for Eclipse 2020-12 yet.