Linux / Fedora 64 - upgraded package and library not work or recognized

while upgrading GTK+ by building the package from the source code from
http://www.gtk.org/download-linux.html, following the simplest steps to build gtk+-2.22.1:

./configure  even failed by dumping :
configure: error: Package requirements (glib-2.0 >= 2.25.10    atk >= 1.29.2    pango >= 1.20    cairo >= 1.6    gdk-pixbuf-2.0 >= 2.21.0) were not met

and grouching that current glib-2.0 version is 2.22.5, lower than the needed.

So, download GLib2.26 from the same site above, and smoothly brought off the building process, everything seems ok.

When resume the ./configure for gtk+ however,  it sticks to the same complaints !

------------   upgrade finished right now is not recognized !


thumb around online discussion and blogs, finally found out the culprit - the path where the upgrade got installed is inconsistent with what pkg-config searches by default.

pkg-config       --modversion glib-2.0
2.22.5

perusing the man page of pkg-config to get know the cause and the solution :

REMOVE the old glibconfig.h before "make install" for the upgrade of glib-2.0, for instance:
rm -rf /usr/lib64/glib-2.0/include/glibconfig.h

get back to glib2.26.1, cd the source path, perform "make install" (since we have done "make" before and not clean up the objects by "make clean". otherwise, should start over from "make" )

and again, pkg-config       --modversion glib-2.0
2.26.1

all right, find it!