When I try to debug my Software_CS (Software Service) module, I am not able to select the Software (Software Catalog UI) module as the entry point.

Things I've tried to solve this:

• Make sure there are no cyclic references.
  • I have verified that there are no cyclic references by using the Discovery app (see the image below)
• Make sure there are no upward references.
  • I have verified this as well, also by using the Discovery app.
• Make sure there are no sideways references from an End-user module.
  • Using the image below from the Discovery app, the Software Catalog app has a sideways reference, which is a reference to the CKEditor app. Software Catalog does consume the Software Catalog Data core app. Please see below for a diagram of how these apps and modules relate to each other. In any case, Software Service is consumed directly by Software Catalog UI, so I would think that Software Catalog would not be affecting this. 
• Make sure that all modules are up-to-date.
  • All modules in the apps listed here are up-to-date.

Debug panel in Software_CS. It shows that Software_CW (in the same app as Software_CS, with both modules being Core modules) is the only available entry module. 

The Discovery app shows that the only issue here is the Software Catalog app with a sideways reference to CKEditor. Note that CKEditor is not a dependency of any of the other apps

Diagram for how the modules relate:

Is the Software Catalog app a poison pill? If so, then if I have a Core app which could be consumed by dozens of other End-user apps and even one of those End-user apps contains a sideways reference, that would prevent debugging those other dozens of apps. Also, I might add that the CKEditor forge component was designed such that it has the editor in a block which is itself in an End-user app, which precludes the ability to use that editor block in any other app.

Any thoughts are appreciated! Thank you!