Unable to build because of dependency on gtk+extra, which appears to be abandonware. gtk+extra won't build on a system with gtk-2.0 installed:
gtkitementry.c:134:21: error: static declaration of ‘gtk_entry_reset_im_context’ follows non-static declaration
/usr/include/gtk-2.0/gtk/gtkentry.h:311:13: note: previous declaration of ‘gtk_entry_reset_im_context’ was here
Since we're already up to gtk-3.0, gtk+extra is obviously extremely crufty. Since gtk+extra won't build, that means gpsim won't build either, making it unusable on anything approaching a modern Linux system.
Please remove the gtk+extra dependency and link to something a little more modern and mainstream so we can use this excellent simulator without having to install something like Red Hat 7.