Fails to parse some classes

Most classes have no problems, but e. g. QRect fails to generate any documentation for some functions:

But the detailed description works fine, as do most classes (e. g. QPoint).

When building the documentation I see this for seemingly everything that fails to get generated (basically incomplete types for everything that fails):

/home/sandsmark/pkg/qt5-doc/trunk/src/qt-everywhere-src-5.12.0/qtbase/src/corelib/tools/qrect.cpp:215: (qdoc) warning: clang found diagnostics parsing \fn QRect::QRect()
error: incomplete type 'QRect' named in nested name specifier

This is the first occurence of `qrect` in the log file, I guess qdoc somehow swallows the warning that leads to it missing the declaration of QRect.

I rebuilt qt5-tools first, to make sure it was built against the currently installed version.