Installing GTK+ 3.8.0

["Mack J. Jenkins" <mack jenkins eas gatech edu>]

I hope this is the right place to send this question.  If it is not, I'm sorry, and can you point me in the 
right direction.

I am trying to install GTK+ 3.8.0 and found out that I have a few items that need to be upgraded.  The 
message I received was;

configure: error: Package requirements (glib-2.0 >= 2.35.3    atk >= 2.7.5    pango >= 1.32.4    cairo >= 
1.10.0    cairo-gobject >= 1.10.0    gdk-pixbuf-2.0 >= 2.27.1) were not met:

No package 'glib-2.0' found - DONE
No package 'atk' found
No package 'pango' found
No package 'cairo' found
No package 'cairo-gobject' found
No package 'gdk-pixbuf-2.0' found


After some trial and error, I found that GLIB needs to be installed 1st.  I have installed GLIB to 

/usr/local/packages/glib/2.34.0

We use RHEL 6 here, and when we install something from source, we separate it out like above because my users 
sometimes need older versions of stuff.  Atk fails the installation saying this;

*** GLIB 2.31.2 or better is required. The latest version of
*** GLIB is always available from ftp://ftp.gtk.org/. If GLIB is installed
*** but not in the same location as pkg-config add the location of the file
*** glib-2.0.pc to the environment variable PKG_CONFIG_PATH.

I have tried a few different ways to assign glib-2.0.pc to the variable PKG_CONFIG_PATH, but it continues to 
fail.  Is there some trick I am missing out on since I am new to ATK and GTK+?  

Any help is much appreciated.
--
Mack J. Jenkins, II
404-385-1591
mack jenkins eas gatech edu
System Support Engineer II
Earth & Atmospheric Sciences