Comment by wizzairflyer

My (admittedly naive) understanding of the ordeal leads me to believe that it is that the 1st would not segfault but the second will since declaring it as a const pointer will create additional memory constraints.

Testing it on my machine with the following code seems to validate this hypothesis.

  //file: test.c
  #include <stdio.h>
  const void * const_pointer = &const_pointer;
  void * const const_value   = &const_value;
  
  int main()
  {
      printf("%p\n", const_pointer);
      *(int*)const_pointer = 0;
      printf("%p\n", const_pointer);
  
      printf("---------------------------\n");
  
      printf("%p\n", const_value);
      *(int*)const_value = 0;
      printf("%p\n", const_value);
      return 0;
  }
  
  Result:
  
  $ gcc test.c
  test.c:4:30: warning: initialization discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
  void * const const_value   = &const_value;
                              ^

  $ ./a.out
  0x55b29ebfc010
  0x55b200000000
  ---------------------------
  0x55b29ebfbdb8

  Command terminated

As to why the first one doesn't also result in a segfault, I don't know.