after having upgraded to a newer version of your Linux distribution.
Giving up.
-ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
+Destroying locked mutex: mutex 0x........, recursion count 1, owner 1.
+ at 0x........: kill (in /...libc...)
+ by 0x........: abort (in /...libc...)
+ by 0x........: vg_set_main_thread_state (drd_pthread_intercepts.c:?)
+ by 0x........: pthread_create* (drd_pthread_intercepts.c:?)
+ by 0x........: nearly_main (../../helgrind/tests/tc09_bad_unlock.c:35)
+ by 0x........: main (../../helgrind/tests/tc09_bad_unlock.c:49)
+
+ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)