Some more information. After I finished lfs I have installed everything in the chapter 24. X Window System Environment, including all dependencies. After that I have installed the following packages in this order:
(GTK+-2.24.13 - not yet installed)
Google showed me this
, so I think it has something to do with gobject-introspection. I guess the problem might be that I installed Pango before gobject-introspection. I'll reinstall Pango and see if it helps.
I'm a bit confused about in which order to install everything. The chapter in the book is not in dependency-order. So I thought I'll start with Openbox, and after that... I'm planlessly installing what I come to think about at the moment...