When using lincomb with an identity matrix it seems LangC causes problems.

Considering that ONE is declared as

    const double ZERO = 0.0;

I believe, this use of ONE should be something different:

https://github.com/jarlebring/GraphMatFun.jl/blob/2558b55495b7bafeaa0b6082105546407b83352f/src/gen_code.jl#L584-L589

which generates code like

    memcpy(memslots+(1-1)*n*n, A, n*n*sizeof(*memslots));
    cblas_dscal(n*n, coeff2, memslots+(1-1)*n*n, 1);
    cblas_daxpby(n*n, coeff1, &ONE, 0,
             ONE, memslots+(1-1)*n*n, n+1);

It segfaults.

The third parameter in axbpy should be a matrix/vector.

I wouldn't mind looking it myself with a hint of what was the plan