[...]
gcc -g -O2 -fdebug-prefix-map=/data/pidentd-3.0.19.ds1=. -fstack-protector-strong -Wformat -Werror=format-security -DHAVE_CONFIG_H -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include/openssl -DPATH_SYSCONFDIR=\"/etc\" -I. -I./src   -c -o idecrypt.o idecrypt.c
In file included from /usr/include/string.h:635:0,
                 from idecrypt.c:17:
In function 'memcpy',
    inlined from 'decrypt_packet' at idecrypt.c:164:5:
/usr/include/x86_64-linux-gnu/bits/string3.h:53:10: warning: call to __builtin___memcpy_chk will always overflow destination buffer
   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In function 'memcpy',
    inlined from 'decrypt_packet' at idecrypt.c:165:5:
/usr/include/x86_64-linux-gnu/bits/string3.h:53:10: warning: call to __builtin___memcpy_chk will always overflow destination buffer
   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[...]