Also, I hate to state the obvious, but make sure your gtk+2 package installed pkgconfig files.
I just started a new gnome-2.18.2 build and libnotify crapped out on me with the same error. For some reason, gtk-2.10.13 isn't installing any pkgconfig files but 2.10.12 did. atleast I think it did... I had to add this to my gtk+2 build script:
Code:
# Strange...
if [ ! -d $PKG/usr/lib/pkgconfig ]; then
mkdir -p $PKG/usr/lib/pkgconfig
install -m 644 *.pc $PKG/usr/lib/pkgconfig
fi
If this is indeed what's going on, then you might want to file a bug report with both DLG and Slackware. But explode both packages to make sure they aren't shipping .pc files first...
From your first post, you already stated that you ran the command:
pkg-config gtk+-2.0 --libs
So... That's probably not it. Unless you didn't do what the error told you to..
The latest pygtk isn't installing header files either... Man I really hate maintaining your own system...
Development files, development files... Check for em cause that's more than likely what's happening.