I find out that the latest Qt 5 update in Fedora 27 (5.9.2) breaks Cura, one of the 3D printing apps.
I've reported the problem [0] (it contains more links).
However, I have no idea how to debug this or fix it, so if anyone here is a Qt mastermind, please help.
[0] https://bugzilla.redhat.com/show_bug.cgi?id=1507859
Thank you,