in /usr/include, add a symlink to ../lib/glib/include/glibconfig.h
glibconfig.h is a system dependent header. Therefore it lives in /usr/lib, not /usr/include. /usr/include is shareable across architectures. The correct gcc line for building glib apps just need to include the directory that glibconfig.h lives by including "-I/usr/lib/glib/include" on the command line.
*** This bug has been marked as a duplicate of 142 ***