Why is the following program not working?

void test(int*[]);
int main()
{
    char *a[2];
    test((int*[])a);
    
    return 0;
}

void test(int* c[]){

}

It shows

error cast to incomplete type ‘int*[]’ test((int*[])a)

The problem can be fixed by using:

test((int**)a);

But what is wrong with the previous code?