Were you able to resolve this error? I am facing an identical issue with this while compiling on OSX.
g++ -o sample/wxFreeChartDemo_dll wxFreeChartDemo_dll_bardemos.o wxFreeChartDemo_dll_bubbledemos.o wxFreeChartDemo_dll_combinedaxisdemos.o wxFreeChartDemo_dll_demo.o wxFreeChartDemo_dll_democollection.o wxFreeChartDemo_dll_ganttdemos.o wxFreeChartDemo_dll_markersdemos.o wxFreeChartDemo_dll_multipleaxisdemos.o wxFreeChartDemo_dll_ohlcdemos.o wxFreeChartDemo_dll_timeseriesdemos.o wxFreeChartDemo_dll_xydemos.o -L./lib -L./lib -Wl,-rpath,../lib -lwxcode_osx_cocoau_freechart-3.1 -L/usr/local/lib -framework IOKit -framework Carbon -framework Cocoa -framework AudioToolbox -framework System -framework OpenGL -lwx_osx_cocoau_core-3.1 -lwx_baseu-3.1 -lwx_osx_cocoau_aui-3.1
Undefined symbols for architecture x86_64:
"wxAboutBox(wxAboutDialogInfo const&, wxWindow*)", referenced from:
MainFrame::OnAbout(wxCommandEvent&) in wxFreeChartDemo_dll_demo.o
"wxAboutDialogInfo::SetVersion(wxString const&, wxString const&)", referenced from:
MainFrame::OnAbout(wxCommandEvent&) in wxFreeChartDemo_dll_demo.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)