[ HELP ] fakePureCalloc error

[wron]

Hey guys, what does this error mean:
`.local/usr/dmd-2.111.0/linux/bin64/../../src/phobos/std/internal/memory.d(39,33): Error: `fakePureCalloc` cannot be interpreted at compile time, because it has no available source code`

I have a class:
```
import std.container.array : Array;

class Sieve(K, V)
{
     alias kvtuple = Tuple!(K, V);
     struct cdata
     {
         kvtuple data;
         cdata* prev;
         cdata* next;
         bool visited;
     }

     cdata* head, tail, hand;
     Array!(cdata) arr;
     int count, len;

     this(int l = 1021)
     {
         len = l;
         arr.length(len);
     }

     ... do more things
}

````
works when I do:
```
Sieve!(string, int) sieve = new Sieve!(string, int); 
sieve.arr.length(1021);
```
and remove the constructor.