Code indexer regression

I have an imported project that is indexed correctly in Qt Creator 2.6.2 but not indexed correctly in 2.8.1. The indexer finishes much too quickly, and even basic things like member variables in an ordinary (non-derived, non-template) class are not indexed.

I can't provide the project source, but is there any sort of debug logging that I can turn on to get some insight into the problem?