I have rebuilt memkeys for stretch-wikimedia, uploaded it to reprepro and tried to use it on mw1238 to sniff some memcached traffic. The result was the following segfault in Thread 2 (got the stacktrace using gdb):
(gdb) thread apply all bt Thread 7 (Thread 0x7fffe77fe700 (LWP 46005)): #0 0x00007ffff73337fd in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x000055555556fcba in ?? () #2 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x555555797f80) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #3 0x00007ffff732a4a4 in start_thread (arg=0x7fffe77fe700) at pthread_create.c:456 #4 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 6 (Thread 0x7fffe7fff700 (LWP 46004)): #0 0x00007ffff679f28d in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x00007ffff679f1da in __sleep (seconds=0) at ../sysdeps/posix/sleep.c:55 #2 0x0000555555570322 in ?? () #3 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x555555797f50) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #4 0x00007ffff732a4a4 in start_thread (arg=0x7fffe7fff700) at pthread_create.c:456 #5 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 5 (Thread 0x7ffff4a6c700 (LWP 46003)): #0 0x00007ffff73337fd in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x0000555555579754 in ?? () #2 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x555555798410) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #3 0x00007ffff732a4a4 in start_thread (arg=0x7ffff4a6c700) at pthread_create.c:456 #4 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 4 (Thread 0x7ffff526d700 (LWP 46002)): #0 0x00007ffff73337fd in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x0000555555579754 in ?? () #2 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x555555797ed0) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #3 0x00007ffff732a4a4 in start_thread (arg=0x7ffff526d700) at pthread_create.c:456 #4 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 3 (Thread 0x7ffff5a6e700 (LWP 46001)): #0 0x00007ffff73337fd in nanosleep () at ../sysdeps/unix/syscall-template.S:84 #1 0x0000555555579754 in ?? () #2 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x555555798370) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #3 0x00007ffff732a4a4 in start_thread (arg=0x7ffff5a6e700) at pthread_create.c:456 #4 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 2 (Thread 0x7ffff626f700 (LWP 46000)): #0 __memmove_sse2_unaligned_erms () at ../sysdeps/x86_64/multiarch/../multiarch/memmove-vec-unaligned-erms.S:242 #1 0x00007ffff70bd52b in std::char_traits<char>::copy (__n=65535, __s2=0x5555557a761c "", __s1=<optimized out>) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/bits/char_traits.h:290 #2 std::basic_streambuf<char, std::char_traits<char> >::xsputn (this=0x7ffff626e948, __s=0x5555557a761c "", __n=140737331596120) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/bits/streambuf.tcc:90 #3 0x00007ffff70ae58e in std::basic_streambuf<char, std::char_traits<char> >::sputn (__n=140737331596120, __s=0x555555797680 "0uyUUU", this=<optimized out>) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/streambuf:451 #4 std::__ostream_write<char, std::char_traits<char> > (__n=140737331596120, __s=0x555555797680 "0uyUUU", __out=...) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/bits/ostream_insert.h:50 #5 std::__ostream_insert<char, std::char_traits<char> > (__out=..., __s=0x555555797680 "0uyUUU", __n=140737331596120) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/bits/ostream_insert.h:101 #6 0x0000555555563a6e in ?? () #7 0x0000555555566fbe in ?? () #8 0x00007ffff705ae6f in std::execute_native_thread_routine (__p=0x5555557971b0) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:83 #9 0x00007ffff732a4a4 in start_thread (arg=0x7ffff626f700) at pthread_create.c:456 #10 0x00007ffff67cfd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97 Thread 1 (Thread 0x7ffff7fe3740 (LWP 45988)): #0 0x00007ffff732b6dd in pthread_join (threadid=140737323136768, thread_return=0x0) at pthread_join.c:90 #1 0x00007ffff705b0f7 in __gthread_join (__value_ptr=0x0, __threadid=<optimized out>) at /build/gcc-6-6.3.0/build/x86_64-linux-gnu/libstdc++-v3/include/x86_64-linux-gnu/bits/gthr-default.h:668 #2 std::thread::join (this=0x5555557985d0) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:136 #3 0x0000555555578221 in ?? () #4 0x0000555555566429 in ?? () #5 0x0000555555578eee in ?? ()