Eljay, Ok, but libXR4000.so uses another lib, name Nhost_client.a (a "closed" lib that I cannot recompile). This lib has the errno object: > nm lib/Nhost_client.a | grep errno U errno U errno U h_errno How can I put in the #include <cerrno> in the libXR4000.so's code? I have put in the #include <cerrno> in the all cpp's files of libXR4000 and recompiled it, but I got the same error. thanks gabriel. >>>>> Hi Gabriel, Based on your command line, I don't see how ./lib/libXR4000.so is involved in the compilat ion/link. Anyway, you'll need to put in the #include <cerrno> in the libXR4000.so's code and recompi le that library. --Eljay _________________________________________________ Quer ajudar o Brasil e não sabe como? AjudaBrasil: http://www.ajudabrasil.org/mail.html.