timing path has same from and to nodes.

This is in the timing report and it is frustrating. Why are from and to nodes same? How to read this timing path?

From Node ; module|testfifo|empty~_Duplicate ;
To Node ; module|testfifo|empty~_Duplicate ;
Launch Clock ; somethingA|somethinB|ch0 ;
Latch Clock ; somethingA|somethinB|ch0 ;
; Data Arrival Time ; 9.774 ;
; Data Required Time ; 9.596 ;
; Slack ; -0.178 (VIOLATED)