So, I managed to get it working. The Arial font doesn't work for me (on Debian testing) but "Nimbus Sans L" did the trick. This font is included in ghostscript package called libgs9-common. It includes Nimbus, URW, Century Schoolbook L, Dingbats and Standard Symbols L. Note that most of these fonts have L on their names, maybe it means something, I dunno. These files are located at /usr/share/ghostscript/9.05/Resource/Font/. I tried some other regular OpenType and TrueType fonts but Linthesia crashes with every of them. Maybe my glibmm/pango/whatever else doesn't have support for these and it was introduced in more recent version. I have no idea. Though "Nimbus Sans L" and "URW Gothic L" work fine here, give it a try if Arial doesn't solve the problem.