I believe that the problem is a glib problem. 
The missing function resides normally in /usr/include/glib-2.0/glib/goption.h .
 In my previous version of glib-2.0 ( glib-2.10.3.ebuild) , the function does not exist , but in the new version ( glib-2.14.3.ebuild) , all is fine . 
Then after re-emerging glib, no problem occurs for emerging desktop-file-utils-0.14 . 
Therefore it's only a minimal version problem, maybe a flag like 
 DEPEND "> dev-libs/glib-2.10.3" or more should avoid the problem.
  Apologizes for my bad english .