I’ve tried to help a fellow on stackoverflow, but got stuck with the unwinder. https://stackoverflow.com/questions/22536198/cant-get-luajit-to-compile-with-cygwin/22599647#22599647 DYNLINK cyglua51.dll lj_vm.o:(.xdata+0x10): undefined reference to `lj_err_unwind_win64' lj_vm.o:(.xdata+0x10): relocation truncated to fit: rva32 against undefined symbol `lj_err_unwind_win64’ Where do I define the win64 style unwinder for cygwin 64bit? Code is in host/buildvm_peobj.o I think that should be just it.