glib basically IS the operating system
it HAS to be installed for the os to be working
so it IS installed
there is no need to install it , because it is installed
also it you replace the version that is installed with a different version you will need to rebuild about 90%+ of the operating system
now for some unnamed source code to build you might need " glib-devel"
the headers and development software
yum install glib-devel