I am running Fedora 26 beta (had the same issue also with 25) with fpc 3.0.2 and lazarus 1.6.4. Both the system version of cqrlog and the one built from the current git repository have a problem with certain fonts. Both the dx cluster window and the window showing recent changes (when running cqrlog for the first time) have extremely small font size (unreadable). I have tried all the font settings (including deselect default fonts in prefs) but nothing seems to help. Whenever a problematic window opens, I see the following message on the terminal window where I started cqrlog:
(cqrlog:19163): GLib-GObject-WARNING **: value "-nan" of type 'gdouble' is invalid or out of range for property 'page-size' of type 'gdouble'
This message does not show up on intel (where the fonts work correctly).
Any ideas what could be wrong?