Our automated tests for the Fedora installer stopped working on the software selection screen with GTK+ 3.17 in Rawhide. It seems like the lists of radio buttons on that screen behave differently between 3.16 and 3.17, with mouse-over and keyboard navigation.

In F22 / GTK+ 3.16 if you tab to the menu and use the up/down arrows to scroll through it, each entry gets a blue highlight as you scroll through. In F23 / GTK+ 3.17, there's only a rather hard to see dotted-line rectangle to indicate the selected entry. In F22 / GTK+ 3.16, entries get a subtle grey highlight as you mouse over them; in F23 / GTK+ 3.17, the grey highlight appears as you mouse over entries but doesn't *disappear* as you mouse away from them in a downwards direction, only as you mouse away in an upwards direction. When you mouse over the entry that's currently active according to the keyboard, it suddenly gets a blue highlight.

This is a bit difficult to describe, so I'm attaching a video comparing the behaviours: F23 / GTK+ 3.17 in the upper VM, F22 / GTK+ 3.16 in the lower VM.