Can it be that you have QT_STYLE_OVERRIDE=gtk exported somewhere? I have just seen a user with that environment variable and similar symptoms, and removing that line helped.
There is no style named “gtk” in Qt 5 (only “gtk2”), so Qt (< 5.8) falls back to the first available style (most likely the “bb10dark” which looks ugly). This behavior was fixed in Qt 5.8 in http://code.qt.io/cgit/qt/qtbase.git/commit/?id=76746ddab6f. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to qtbase-opensource-src in Ubuntu. https://bugs.launchpad.net/bugs/1695618 Title: Qt5 apps don’t pick up the GTK+ style anymore Status in qtbase-opensource-src package in Ubuntu: New Bug description: Since I upgraded to Qt 5.7.1, Qt5 apps stopped picking up the Ubuntu (GTK+, I presume) theme, and look very Windowsy. I have qt5-gtk- platformtheme installed, and I tried forcing it by setting QT_QPA_PLATFORMTHEME, but to no avail. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1695618/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
