Don't use stacktrace on Windows.

src/Exception.hpp

@@ -1,6 +1,8 @@
 #ifndef ARBUTILS_EXCEPTION_HPP
 #define ARBUTILS_EXCEPTION_HPP
+#if !WINDOWS
 #define BACKWARD_HAS_BFD 1
+#endif
 
 #include <exception>
 #include <sstream>
@@ -34,7 +36,7 @@ namespace ArbUt {
                         function += "...";
                     }
                     ss << objectName;
-                    if (include_addr){
+                    if (include_addr) {
                         ss << "[" << trace.addr << "]";
                     }
                     ss << " " << function << std::endl;