Undefined symbols for architecture x86_64

[xx_C_xx]

I am fairly new to qt development.
I have a project which I try to build and have some problems compiling it.
It is linked with some OGRE files and I get the error when compiling it
Undefined symbols for architecture x86_64
I guess I have to change the compiler but don*'t know to which
Any help?

[SGaist]

Hi and welcome to devnet,

Which compiler was used to build OGRE ?