[Qt-creator] QtCreator on F29

[Richard Kimberly Heck]

Since upgrading to Fedora 29 (yes, I tend to be a bit behind), I've been
having problems using QtCreator as I always have to work on LyX.
Specifically, QtCreator fails to find a lot of included files, with the
result that there are gazillions of 'parse errors' displayed in the
editor. For example, our own generated config.h is not found, and
QtCreator complains that none of the Qt headers are found.

Any idea what has changed or what I might do? I've tried deleting all
the *.creator files, etc.

Riki