As it treats warnings as errors, I'm suprised it compiled on Linux as a printf expects a long int, but gets a time_t. Anyway, patch to follow.
Created attachment 103880 [details, diff] Cast the time_t
Can't find an upstream location to report this, so gnome team will have to handle this.
libxklavier-3.1 is in the tree now and that version doesn't use -Werror. This should work too, as discussed earlier on IRC. I'll make sure I eventually have upstream take care of the warning.