synapse crashes on vivid : core dumped

I'm Sorry : still affects Xubuntu if not Ubuntu :

:~$ synapse
[INFO 23:38:56.488307] [synapse-main:268] Starting up...
[WARN 23:38:56.553380] [Gtk] Theme parsing error: gtk.css:27:35: Junk at end of value
[WARN 23:38:56.558249] [Gtk] Theme parsing error: gtk.css:40:48: Junk at end of value
[WARN 23:38:56.562975] [Gtk] Theme parsing error: gtk.css:48:46: Junk at end of value
[WARN 23:38:56.567607] [Gtk] Theme parsing error: gtk.css:59:58: Junk at end of value
[WARN 23:38:56.572213] [Gtk] Theme parsing error: gtk.css:70:46: Junk at end of value
[WARN 23:38:56.576587] [Gtk] Theme parsing error: gtk.css:81:58: Junk at end of value
[WARN 23:38:56.644258] [GLib-GObject] The property GtkButton:use-stock is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.668638] [GLib-GObject] The property GtkSettings:gtk-button-images is deprecated and shouldn't be used anymore. It will be removed in a future version.
[INFO 23:38:56.670542] [synapse-main:211] Binding activation to <Control>space
[WARN 23:38:56.705101] [GLib-GObject] The property GtkMisc:xpad is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.729276] [GLib-GObject] The property GtkSettings:gtk-menu-images is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.755335] [GLib-GObject] The property GtkImageMenuItem:accel-group is deprecated and shouldn't be used anymore. It will be removed in a future version.
[INFO 23:38:56.761772] [view-base:251] Screen is composited.
[INFO 23:38:56.762692] [controller:59] Using xim input method.
[WARN 23:38:56.781172] [GLib-GObject] The property GtkMisc:ypad is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.882870] [GLib-GObject] The property GtkAlignment:left-padding is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.905802] [GLib-GObject] The property GtkAlignment:top-padding is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.929754] [GLib-GObject] The property GtkAlignment:right-padding is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.953907] [GLib-GObject] The property GtkAlignment:bottom-padding is deprecated and shouldn't be used anymore. It will be removed in a future version.
[WARN 23:38:56.967306] [desktop-file-service:193] Le fichier de clés ne contient pas de clé « Type » dans le groupe « Desktop Entry »
[WARN 23:38:56.967997] [desktop-file-service:193] Le fichier de clés ne contient pas de clé « Type » dans le groupe « Desktop Entry »
[WARN 23:38:56.968753] [desktop-file-service:193] Le fichier de clés ne contient pas de clé « Type » dans le groupe « Desktop Entry »
[WARN 23:38:56.969223] [desktop-file-service:193] Le fichier de clés ne contient pas de clé « Type » dans le groupe « Desktop Entry »
[WARN 23:38:56.969440] [desktop-file-service:193] Le fichier de clés ne contient pas de clé « Type » dans le groupe « Desktop Entry »
[WARN 23:38:56.970017] [desktop-file-service:193] Le fichier de clés ne contient pas de clé ...

While it may affect Ubuntu, as far as I know synapse is not a part of the official Ubuntu archive and that's why I removed the Ubuntu task.

Got the point !

...& still get "core dumped" ;)

Mario's workaround (diodesis) anounced on bug#1401909 :

launch synapse with :

$ GTK_IM_MODULE='' synapse

works on my Xubuntu 15.04.