With new gcc9 how to handle error from -Werror=address-of-packed-member

[Normand]

With new gcc9 there are new error reported by 
-Werror=address-of-packed-member
How to handle such error ?

eg:
libflash/ecc.c:419:24: error: taking address of packed member of 'struct 
ecc64' may result in an unaligned pointer value 
[-Werror=address-of-packed-member]
   419 |   memcpy(inc_uint64_by(&ecc_word.data, alignment), src, 
bytes_wanted);
       |                        ^~~~~~~~~~~~~~

-- 
Michel Normand