Comment 0 for bug 1750794

The official version shipped with Ubuntu 16.04 LTS is an unstable branch of Eigen 3.3 (i.e. Eigen 3.3-beta1)

This is very inconvenient for a LTS version of Ubuntu, considering that even the following simple code gives SEGFAULT:

#include <iostream>
#include <Eigen/Dense>

using namespace std;
using namespace Eigen;

int main()
{
    Eigen::Vector3d b = Eigen::Vector3d::Random();
    Eigen::MatrixXd A = Eigen::MatrixXd::Random(3,3);

    std::cout << "The following code crashes from Eigen 3.3-beta1 to Eigen 3.3-RC1" << std::endl;
    std::cout << -A*b << std::endl;

    return 0;
}

I strongly suggest either to upgrade to the stable branch of 3.3 (i.e. 3.3.4) or the stable branch of the 3.2 (i.e., 3.2.10), for which the problem doesn't hold.

Note that I'd rather prefer not to install one of these stable versions myself, because lots of other packages for this release are built on top on the libeigen3-dev.

If I link those packages against my custom libraries, I would have two different versions of Eigen to co-exist in the same binary.