configure: error:
The development files for GTK+ were not found. For GTK+ 2, please
ensure that pkg-config is in the path and that gtk+-2.0.pc is
installed. For GTK+ 1.2 please check that gtk-config is in the path,
and that the version is 1.2.3 or above. Also check that the
libraries returned by 'pkg-config gtk+-2.0 --libs' or 'gtk-config
--libs' are in the LD_LIBRARY_PATH or equivalent.