Patch from upstream to allow compilation with glib 2.16:
http://ruby-gnome2.svn.sourceforge.net/viewvc/ruby-gnome2/ruby-gnome2/trunk/glib/src/lib/glib-mkenums.rb?r1=2345&r2=2848
--- glib/src/lib/glib-mkenums.rb.~1~	2006-12-29 14:17:28.000000000 +0100
+++ glib/src/lib/glib-mkenums.rb	2008-03-28 07:18:21.475004713 +0100
@@ -33,14 +33,12 @@
       if const_lines.include? "<<"
         @type = "flags"
         @Type = "Flags"
-        regexp = /^\s*([^\s]*)\s.*\n/
-      else
+       else
         @type = "enum"
         @Type = "Enum"
-        regexp = /^\s*([^\s,]*).*\n/
       end
       consts = []
-      const_lines.scan(regexp){|name|
+      const_lines.scan(/^\s*([^\s,]*).*\n/){|name|
         consts << name[0] unless name[0] =~ /(^[\/\*]|^$)/
       }
       @prefix = extract_prefix(consts)