I can create and use treeview widgets from within my 'main' function. However, gtk2's treeview functions segfault if called from anywhere but main.

My local functions are just labels. I rarely have need for anything more formal than that.

Anybody have any idea why gtk2's treeview widget would crash like that? Makes no sense to me at all.

I haven't (yet) found any other window, container, widget or controll that has this problem.

Archlinux 64-bit
glib2 2.32.3
gtk2 2.24.10
gtk2+extra 2.1.2 (the pre-made treeviews have the same problem)
glibc 2.15

Hmm, when 64-bit Linux has crashed for me in the past, it's generally due to a misaligned stack. It's possible that somewhere deep within the treeview functions, some floating point instructions are used which expect the stack pointer to be a multiple of 16 bytes. If your functions are just labels, then they will start with a misaligned stack (due to the 8-byte return address). This would also explain why the gtk+ functions work in "main" but not elsewhere. You probably aligned the stack correctly at the beginning of "main" by pushing RBP. It's just a possibility though, obviously I may be completely wrong.

Good call, I hadn't thought of that.
Stack alignment was definitely the problem, thanks for the heads-up.