Hello, Again, you need to tell us what you are doing. Are you compiling under GNU/Hurd or under GNU/Linux? Always remember the xy problem https://xyproblem.info/
Ahmed Khider, le ven. 17 juil. 2026 20:43:54 +0300, a ecrit: > When I tried to compile my c file, the linker > > throw an error : undefined reference to Since it's an undefined reference, the problem is *not* a missing header, but an missing link piece. But mach_msg is normally provided by the libc, so that can't be a missing flag or such, but rather a problem with your compilation chain. Thus back to the question: what are you actually doing? Samuel
