message: fixed a uint64_t to size_t convert problem in manyvars testing
diff: */
  #include "adios2_c.h"
  #include <errno.h>
  +#include <stddef.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  @@ -357,8 +358,8 @@ int read_file()
  double tb, te, tsched;
  double tsb, ts; // time for just scheduling for one step/block
  - uint64_t start[2] = {offs1, offs2};
  - uint64_t count[2] = {ldim1, ldim2};
  + size_t start[2] = {offs1, offs2};
  + size_t count[2] = {ldim1, ldim2};
  uint64_t ndim;
  reset_readvars();
  