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

bug tracking system

    (BTS) A system for receiving and filing bugs
   reported against a software project, and tracking those bugs
   until they are fixed.  Most major software projects have their
   own BTS, the source code of which is often available for use
   by other projects.

   Well known BTSs include GNATS, Bugzilla, and Debbugs.

   (2002-06-12)