B&R Automation Studio compile error: undefined reference to `FileOpen’

I was working with another programmer in the same Automation Studio project that was shared using SVN, and after a new SVN checkout I had this compiler error message:

Error : undefined reference to `FileOpen’

So it looked like someone started using some file handling library, looking around the documentation I realize that it is the FileIO library. The undefined reference means the corresponding binary file was not found by the compiler…