Loading a sparse matrix Armadillo C++ - c++

Question

I'm having a bit of a strange problem. I generally use the CLion IDE to compile and run code but I want to make use of a profiler to try to optimize my software and CLion does not include a profiler extension. So I need to compile and run at command line.
OK, no problem but for some reason when I do so, I get errors when loading sparse matrices saved in the form arma_binary (which the Armadillo documentation states is the only possible file format for sparse matrices).
The following is an example script saved as main.cpp:
#include <iostream>
#include <armadillo>
using namespace std;
using namespace arma;
void DenseMult (mat& I, mat& B);
void SparseMult (sp_mat& I, mat& B);
int main() {
mat Int; Int.load("intMatDense.mat");
cout << Int.n_cols << endl;
sp_mat IntSp; IntSp.load("intMatSparse.mat", arma_binary);
cout << IntSp.n_cols << endl;
mat B; B.load("biomassMat.mat");
DenseMult(Int, B);
SparseMult(IntSp, B);
return 0;
}
void DenseMult (mat& I, mat& B) {
I * B;
}
void SparseMult (sp_mat& I, mat& B) {
I * B;
}
Which gives the following output when built and run in CLion:
/home/jack/CLionProjects/Optimization/cmake-build-debug/Optimization
307
307
Process finished with exit code 0
So far so good but when I do (what I think is) the same at the command line:
jack#jack-MacBookPro:~/CLionProjects/Optimization$ g++ main.cpp -o main -O2 -larmadillo
jack#jack-MacBookPro:~/CLionProjects/Optimization$ ./main
I get the following output:
307
warning: SpMat::load(): inconsistent data in intMatSparse.mat
0
error: matrix multiplication: incompatible matrix dimensions: 0x0 and 307x3
terminate called after throwing an instance of 'std::logic_error'
what(): matrix multiplication: incompatible matrix dimensions: 0x0 and 307x3
Aborted (core dumped)
Is it possible I need to link to the Armadillo library differently in order to access the sparse matrix functionality?
Thanks in advance.
Jack