message: code review: really bad copy/paste...
diff: // Make compilation fail - required for external projects - https://github.com/GUDHI/gudhi-devel/issues/10
  #if !EIGEN_VERSION_AT_LEAST(3,1,0)
  -# error Alpha_complex is only available for Eigen3 >= 3.1.0 installed with CGAL
  +# error Edge Collapse is only available for Eigen3 >= 3.1.0
  #endif
  namespace Gudhi {
  