American Fuzzy Lop (http://lcamtuf.coredump.cx/afl/), a fuzzer which instruments programs at compile-time to help find interesting inputs faster than brute-force fuzzing.
It may have indeed found a bug in TimSort, since it's more apt at exercising branches, but I think AFL is C/C++ only.
It may have indeed found a bug in TimSort, since it's more apt at exercising branches, but I think AFL is C/C++ only.