Re: Set font size of a label using Pango attributes
I just tested this on Debian 9 "Stretch". The first problem is you need to 'use Pango'. Gtk3 does not automatically 'use Pango', so it will not find parts of Pango. I'm far from being an expert, so I'm not sure why it can skip 'Pango::AttrList->new()' without a problem, but it may expose certain parts of Pango through Gtk3.