The Free On-line Dictionary of Computing (30 December 2018):

GNU Problem Report Management System
GNATS

    (GNATS) GNU's bug tracking system.  Users
   who experience problems use electronic mail, web-based or
   other clients communicating with the GNATS network daemon
   running at the support site, or direct database submissions to
   communicate these problems to maintainers at that Support
   Site.

   (http://gnu.org/software/gnats).

   (2002-06-12)