> On April 10, 2019 2:01:23 PM GMT+03:00, Uwe Brauer <oub@mat.ucm.es> wrote:

   > This is already supported: disable the left fringe, and Emacs will
   > show breakpoints in the left display margin, as it does on text-mode
   > terminals.

Hm I tried out

(fringe-mode 1)
(set-fringe-mode '(0 . 0))
(set-fringe-mode '(0 . 1))

But nothing helped, gud-break does not show anything.

I am using emacs master compiled a couple of weeks ago.