assigning a spore to a tendril returns a non-explicit error

[vrabaud]

yeah, I know, why would somebody do that, but no line number is returned in the error:

ecto.TypeMismatch: exception_type TypeMismatch
cell_name g2o::SBA
to_typename ecto::spore<std::vector<Eigen::Matrix<double, 3, 1, 0, 3, 1>, std::allocator<Eigen::Matrix<double, 3, 1, 0, 3, 1> > > >
from_typename std::vector<Eigen::Matrix<double, 3, 1, 0, 3, 1>, std::allocator<Eigen::Matrix<double, 3, 1, 0, 3, 1> > >
function_name process

[ethanrublee]

Should this be a compile time error?