>> In fact, the error 'Error returned 47 at 5417' is NOT reproducible, while
>> segmentation fault occurs each times.
>
> With the same stack???
>

yes :

....
(no debugging symbols found)

Program received signal SIGSEGV, Segmentation fault.
0x080df255 in sqli_connect_set ()
(gdb) where
#0 0x080df255 in sqli_connect_set ()
#1 0x08090c0d in part_tdDtor ()
#2 0x08090b5e in syncVar_tdDtor ()
#3 0x08092382 in checkRepl ()
#4 0x0809112f in cdr_check ()
#5 0x0804ee22 in sync_repl ()
#6 0x0804bf06 in main ()
(gdb)