Dear friendly Qt devs at Debian:

Users coming from older Qt-using environments to KDE Plasma (like me), and
perhaps fresh useru accounts, may have set the
QT_SCALE_FACTOR_ROUNDING_POLICY environment variable to one of its permitted
values[1] to control when and how Qt6 applies fractional scaling in a
semi-high DPI environment. If they do so, they will see a spurious error
message from any Qt app at startup, regardless of the value
QT_SCALE_FACTOR_ROUNDING_POLICY is set to (it just needs to be set,
including to an empty string):

There is an upstream bug about this message, and a fix has been merged for
6.10.0. Is there any chance of a backport to Debian 13 trixie?

* https://bugreports.qt.io/browse/QTBUG-132430
* https://codereview.qt-project.org/c/qt/qtbase/+/631734

I'm using a Plasma on Wayland session under sddm, the standard Breeze
themes, and my everyday QT environment variables are set thus:

I'm running a Wayland display at 150% scaling. I don't think I'm doing
anything particularly weird with this setup, although I could probably drop
a couple of historical environment settings now.



    cheers,
    Andrew


[1] "Supported values are: Round, Ceil, Floor, RoundPreferFloor,
PassThrough."