Comment 7 for bug 1716068

Sometimes crash reports don't work reliably. I can confirm it failed to log a new bug for you:
  https://bugs.launchpad.net/~jstevz4teh1337/+reportedbugs?orderby=-id&start=0

Of course, you shouldn't be running 'gnome-shell --replace' normally unless it's already crashed beforehand. Had it crashed before you ran that command? Even still, it sounds like a dangerous way to restart the shell because the act of it restarting might kill your terminal which is now the parent of the shell. So restarting the shell like that could make it crash immediately, unless you also do:

  nohup gnome-shell --replace &

Please answer the question in the previous paragraph and also try the above more correct command instead.