lldb asked me to submit this bug report so I am. I am debugging some modifications I'm making to fluent-bit. fluent-bit is a threaded C program. The FreeBSD box is running under KVM (up to date Ubuntu 20.04 host) on workstation hardware with ECC RAM. I've had lldb crash on me a few times now. Below is the latest output from the full run minus the program output. # lldb --arch x86_64 -- /usr/local/bin/fluent-bit -c /usr/local/etc/fluent-bit/fluent-bit.conf -s 4096 (lldb) target create --arch=x86_64 "/usr/local/bin/fluent-bit" Current executable set to '/usr/local/bin/fluent-bit' (x86_64). (lldb) settings set -- target.run-args "-c" "/usr/local/etc/fluent-bit/fluent-bit.conf" "-s" "4096" (lldb) run Process 16204 launching Process 16204 launched: '/usr/local/bin/fluent-bit' (x86_64) .... fluent-bit output ..... Process 16204 stopped * thread #2, name = 'fluent-bit', stop reason = signal SIGBUS: hardware error frame #0: 0x0000000800c28945 libc.so.7`files_servent(retval=0x0000000801a6e400, mdata=0x0000000800f92210, ap=0x0000000801a6e400) at getservent.c:281:26 (lldb) bt all Program aborted due to an unhandled Error: Error value was Success. (Note: Success values must still be checked prior to being destroyed). PLEASE submit a bug report to https://bugs.freebsd.org/submit/ and include the crash backtrace. Stack dump: 0. Program arguments: lldb --arch x86_64 -- /usr/local/bin/fluent-bit -c /usr/local/etc/fluent-bit/fluent-bit.conf -s 4096 1. HandleCommand(command = "bt all") 2. HandleCommand(command = "thread backtrace all") #0 0x0000000003ae7aee PrintStackTrace /usr/src/contrib/llvm-project/llvm/lib/Support/Unix/Signals.inc:564:13 #1 0x0000000003ae5fa5 RunSignalHandlers /usr/src/contrib/llvm-project/llvm/lib/Support/Signals.cpp:69:18 #2 0x0000000003ae8060 SignalHandler /usr/src/contrib/llvm-project/llvm/lib/Support/Unix/Signals.inc:0:3 #3 0x0000000804c35e00 handle_signal /usr/src/lib/libthr/thread/thr_sig.c:0:3 Abort trap