error 0
 crypto_sign_open with c=t overlap returns nonzero
 ==15007== Memcheck, a memory error detector
 ==15007== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
 ==15007== Using Valgrind-3.15.0.GIT and LibVEX; rerun with -h for copyright info
 ==15007== Command: ./try
 ==15007==
 ==15007==
 ==15007== HEAP SUMMARY:
 ==15007==     in use at exit: 43,920 bytes in 10 blocks
 ==15007==   total heap usage: 640 allocs, 630 frees, 234,229 bytes allocated
 ==15007==
 ==15007== LEAK SUMMARY:
 ==15007==    definitely lost: 0 bytes in 0 blocks
 ==15007==    indirectly lost: 0 bytes in 0 blocks
 ==15007==      possibly lost: 43,920 bytes in 10 blocks
 ==15007==    still reachable: 0 bytes in 0 blocks
 ==15007==         suppressed: 0 bytes in 0 blocks
 ==15007== Rerun with --leak-check=full to see details of leaked memory
 ==15007==
 ==15007== For lists of detected and suppressed errors, rerun with: -s
 ==15007== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)