Glib needs to be used with some extra flags passed to GCC. These flags are managed by pkg-config. For example: Code: $ pkg-config --libs glib-2.0 -lglib-2.0 $ pkg-config --cflags glib-2.0 -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include So, how can I get those information in autotools? Where should I put them (in configure.ac or Makefile.am)?