Breakpoints don't work because of path capitalization

Update: I think this is related to 

1. QTCREATORBUG-18007

The breakpoints I set in one C++ file don't work. The code is being executed, because I can add log statements and set breakpoints on them that don't work, despite their output appearing in the console.

Breakpoints set in a sibling file in the same module work. I haven't tried to find other files that are afflicted by the problem.

I've tried the usual cleaning, deleting build directories, restarting Qt Creator. No dice.

I've verified that it's a Debug build. I found a similar report here: https://forum.qt.io/topic/134124/qt-creator-will-not-break-in-one-class