[Help-gsl] gsl alloc runtime error

[Petr Ent]

i have been experiencing troubles with allocating objects with gsl functions
i copied example code of nonlinear fitting from manual. it could be compiled 
and linked with no problem. but when i run it and call some memory-allocation 
function, it crashes because of  "AccesViolation runtime error in libgsl.dll"

here is the code
       const gsl_multifit_fdfsolver_type *T;
       gsl_multifit_fdfsolver *s;
     
       int status;
       size_t i, iter = 0;
     
       const size_t n = N;
       const size_t p = 3;
     
       gsl_matrix *covar = gsl_matrix_alloc (p, p);
       double y[N], sigma[N];
       struct data d = { n, y, sigma};
       gsl_multifit_function_fdf f;
       double x_init[3] = { 1.0, 0.0, 0.0 };
       gsl_vector_view x = gsl_vector_view_array (x_init, p);
       const gsl_rng_type * type;
       gsl_rng * r;
     
       gsl_rng_env_setup();
     
       type = gsl_rng_default;
       r = gsl_rng_alloc (type); 
<--------------------------------------------------- this causes crash
     
       f.f = &expb_f;
       f.df = &expb_df;
       f.fdf = &expb_fdf;
       f.n = n;
       f.p = p;
       f.params = &d;
     
       /* This is the data to be fitted */
     
       for (i = 0; i < n; i++)
         {
           double t = i;
           y[i] = 1.0 + 5 * exp (-0.1 * t)
                      + gsl_ran_gaussian (r, 0.1);
           sigma[i] = 0.1;
           printf ("data: %d %g %g\n", i, y[i], sigma[i]);
         };
     
       T = gsl_multifit_fdfsolver_lmsder;
       s = gsl_multifit_fdfsolver_alloc (T, n, p);
       gsl_multifit_fdfsolver_set (s, &f, &x.vector);

when i comment it out, it crashes at next alloc 
("s=gsl_multifit_fdfsolver_alloc (T, n, p);" line)
anybody has some idea what it is caused by?

Petr Ent