The previous error message would show up even if Eigen is not available and the user has passed a solver traits. Reported in https://github.com/CGAL/cgal/issues/4442#issuecomment-570511774
The previous error message would show up even if Eigen is not available and the user has passed a solver traits. Reported in https://github.com/CGAL/cgal/issues/4442#issuecomment-570511774