Hi everybody, I am working on a project that consist in compiling a Windows application on Mac. The application is written in C++ with Qt. It is composed with libraries and the main project : http://hpics.li/d8bb2ec The project uses an external library, ODA, to manage .dwg and .dgn files. The problem is when I compile the first library (MdCore), I get an error : symbol(s) not found for architecture x86_64. At first I added -stdlib=libstdc++ to qmake argument but Qt generated me 0 byte files, so it was not the solution. I have tried different version of the ODA libary : 32bit, 64bit for OSX 10.7 and 10.11. (My Mac is on OSX 10.11) I made the command "file" on my libraries and here the output : <ervery ODA lib> : <lib>.a: current ar archive random library <other lib on /usr/lib>.dylib : Mach-0 universal binary with 2 architectures (for architecture x68_64): Mach-0 64-bit dynamically linked shared library x86_64 (for architecture i386): Mach-0 dynamically linked shared library i386 I have tried to compile on 32 and 64bit but it does not change anything. I am on this problem for two weeks I don't know what I can do I have made a topic on the Qt forum maybe you can find more information : https://forum.qt.io/topic/69171/compile-generate-0-byte-files-on-os-x/11 If someone have a clue or a solution I will be interested Thanks !