Bug in gnatstub

[porton@ex-code.com (Victor Porton)]

I post this message o the NG, not by e-mail because I haven't
found any email for bug reports in the GNAT docs.

$ gnatstub parser.ads
parser.ads:9:04: cannot find body of generic package "Extractor_Info"
gnatstub: cannot create the tree file for parser.ads

generic
package Parser is

   generic
   package Extractor_Info is
      procedure Do_Next_Variant;
   end Extractor_Info;

   package Single_Token_Info is
      new Extractor_Info;

end Parser;