the newly backported package telegram-desktop fails to start due to a segfault.
Here the relevant lines in log:
[2017.09.29 17:55:53] Font Error: could not locate 'Open Sans Semibold' font in ':/gui/fonts/OpenSans-Semibold.ttf'.
[2017.09.29 17:55:53] Could not load 'appindicator3' with version 1 :(
[2017.09.29 17:55:53] Error: failed to load 'gdk_set_allowed_backends' function!
I really don't understand the line about Open Sans Semibold, which is regularly installed in my system.