Solved from the Qt side.

[Lisandro Damián Nicanor Pérez Meyer]

Version: 5.11.1+dfsg-1

The bug upstream has been closed as invalid (see https://bugreports.qt.io/
browse/QTBUG-62511) Non the less a workaround has been included in Qt 5.11, 
already in experimental. Setting QT_RCC_SOURCE_DATE_OVERRIDE should be enough 
to solve this issue.

Now the point is: where should this variable be set?

I guess dh's cmake and qmake helpers might be a good place to start with, but 
I think you might have a bteer undesrtanding of this.

After all forcing the variable will mean also already reproducible builds will 
get modified.

Cheers!

-- 
18: Como se pueden evitar los problemas de alimentacion electrica
    * No coma cerca de un enchufe
    Damian Nadales
    http://mx.grulic.org.ar/lurker/message/20080307.141449.a70fb2fc.es.html

Lisandro Damián Nicanor Pérez Meyer
http://perezmeyer.com.ar/
http://perezmeyer.blogspot.com/
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