I just had an interesting experience.

I decided I needed to start writing Gtk+ apps in 2.0, so I started out
with the helloworld code in the 2.0 tutorial. Cut and pasted. When I
tried to compile it, the errors looked like I was compiling the kernel:
just kept on rolling the screen!

After due consultation with the Gtk+ folk, I downloaded the source code
for the version of Gtk+ included with 10.0: gtk+2-2.4.3-i486-1. The
source code was gtk+-2.4.3. Compiled and installed it on the /usr/local
level.

Comparing the installed header files for gdk-pixbuf was a revelation:
wildly different! Looked like someone had added a bunch of stuff to
several header files and even included two *.xh files in the Slackware
package. What is going on here?

Where did Pat Volkerding get his packages? Or did he modify them
himself? I know he doesn't like Gnome, but have never heard anything
about the gtk code. Gtk+-1.2 works just fine, incidentally.

Anyone have a clue about this? My installation is still box stock: all
new stuff is at /usr/local, leaving /usr strictly distro stuff.

I guess the point is that unless this is resolved, I'll not be inclined
to trust Slackware development packages in the future, and that's a Bad
Thing (tm)!

Longfellow