I didn't look at it too much, but my suspicion is a change in GTK. The crash was on line 187 of sealed.c free(both->S->store);free(both->S->selected); Which is immediately after: gtk_widget_destroy(both->win); If I comment out all the frees, the game is fine (might be leaking, but no more double free). gtk_widget_destroy(both->win); /* Remove the frees due to a crasher. free(both->S->store);free(both->S->selected); free(both->B->store);free(both->B->selected); free(both->S);free(both->B);free(both); */ Might be the destroy cleans things up better now.
Package removed.