How do I properly use LibIGL's AABB.signed_distance() function?

Question

I'm trying to use LibIgl to get the squared distance from a point to the mesh. Here's a code snippet I'm trying to run:

// load a mesh
 std::ifstream fileStream;
 std::string filePath = R"(C:\path\to\stl\1x1x1Cube.stl)";
 Eigen::MatrixXd Vs;
 Eigen::MatrixXi Fs;
 Eigen::MatrixXd Ns;
 igl::readSTL(filePath, Vs, Fs, Ns);

 // build the AABB tree for the mesh
 igl::AABB<Eigen::MatrixXd, 3> tree;
 tree.init(Vs, Fs);

 Eigen::MatrixXd queryPoint = (Eigen::MatrixXd(1, 3) << 0.5, 0.5, 0.5).finished();
 Eigen::VectorXd sqrD;
 {
   Eigen::VectorXi I;
   Eigen::VectorXd C;
   tree.squared_distance(Vs, Fs, queryPoint, sqrD, I, C);
 }

However, when I run this code, it fails on the call to tree.squared_distance(). It's failed an assert somewhere deep inside Eigen. The failed assert is in the Eigen library, in Block.h when it's trying to run the Dynamic-size constructor inline Block().

For what it's worth, the assert that fails is eigen_assert(a_startRow <= xpr.rows() - blockRows)

I'm new to both LibIgl and Eigen. Is there something obvious that I'm missing?