Running the following program:

http://play.golang.org/p/5fVqgRKWIC

produces:

panic: panic during panic
 [process exited with non-zero status]

Program exited.

without any further information. While clearly a program error, one would expect some
indication as to where the last panic happened; and ideally a stack trace.

(This example is a whittled-down version of a much larger program where tracking down
the error was much harder.)