Over the weekend due to some confusion about Java version dependencies and where/if the errors should be picked up we identified that some of CDTs bundles did not have API Tooling enabled. This is an oversight that makes it difficult to identify when API gets broken by simple changes.
For CDT 10 M3 and beyond API Tooling will be enabled on all bundles to make it easier to understand how we may have changed API for our consumers. Note that for experimental and preview bundles (as marked in their name) this does not change the stability of those APIs.
See Bug 566334
for more details and to add your comments.