No memory loss results in script failure

J'obtenais cette erreur:

stderr:
==19481== Memcheck, a memory error detector
==19481== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==19481== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==19481== Command: bin/test
==19481==
==19481==
==19481== HEAP SUMMARY:
==19481==     in use at exit: 0 bytes in 0 blocks
==19481==   total heap usage: 3 allocs, 3 frees, 76,808 bytes allocated
==19481==
==19481== All heap blocks were freed -- no leaks are possible
==19481==
==19481== For counts of detected and suppressed errors, rerun with: -v
==19481== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

Traceback (most recent call last):
  File "evalModuleImage.py", line 350, in <module>
    nb_bytes_lost = int(str_stderr[istart + 17:iend])
ValueError: invalid literal for int() with base 10: "ck, a memory error detector\n==19481== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.\n==19481== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info\n==19481== Command

J'imagine que le problème venait du fais que du coup le script ne trouve pas le texte recherché et est donc incapable de selectionné une partie du texte et dès lors il n'est pas possible de convertir en entier le texte...