Had a quick look for 'Neroden's Github' and can't seem to find it?
https://github.com/neroden/simutrans/tree/ncn-develI can't compile it myself, however... I get:
1>simgraph16.obj : error LNK2005: "void __cdecl mark_rect_dirty_wc(short,short,short,short)" (?mark_rect_dirty_wc@@YAXFFFF@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl activate_ribi_clip(int)" (?activate_ribi_clip@@YAXH@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl clear_all_poly_clip(void)" (?clear_all_poly_clip@@YAXXZ) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl add_poly_clip(int,int,int,int,int)" (?add_poly_clip@@YAXHHHHH@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl display_set_clip_wh(short,short,short,short)" (?display_set_clip_wh@@YAXFFFF@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "struct clip_dimension __cdecl display_get_clip_wh(void)" (?display_get_clip_wh@@YA?AUclip_dimension@@XZ) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl display_set_height(short)" (?display_set_height@@YAXF@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "short __cdecl display_get_height(void)" (?display_get_height@@YAFXZ) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "void __cdecl display_set_actual_width(short)" (?display_set_actual_width@@YAXF@Z) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "short __cdecl display_get_width(void)" (?display_get_width@@YAFXZ) already defined in simgraph0.obj
1>simgraph16.obj : error LNK2005: "short __cdecl display_set_base_raster_width(short)" (?display_set_base_raster_width@@YAFF@Z) already defined in simgraph0.obj