Our org.jboss.tools.common.mylyn plugin uses org.eclipse.mylyn.tasks.bugs.support extension point.
And our common.mylyn plugin depends on org.eclipse.mylyn.tasks.core which depends on org.eclipse.mylyn.tasks.bugs where this extension point is declared.
But org.eclipse.mylyn.tasks.bugs was removed from Beta1 target platform: JBIDE-16368
We don't have any source files in common.mylyn so tycho build works w/o any errors. But plugin.xml validation in my dev eclipse detected this problem.

So we should get the org.eclipse.mylyn.tasks.bugs.support and everything we indirectly depends on back.