I was wanting to write this on a keyboard, but let me try on the phone and see if we can all agree in one point.
There is one *excellent* method to settle this once and forever: submit the __FILE__ patch to GCC devs. If it gets accepted then Qt and whatever project is affected should change it.
If it does not gets accepted then it's a Debian regression.
Until that is done I will consider this a non-Qt bug but a GCC regression. Show me that GCC upstream devs agree with you Xi and I'll happily forward the bug to Qt upstream.
Lisandro