backtrace printing regression on FreeBSD

[xanderio]

When a rust program panics and RUST_BACKTRACE is set the process is killed with a SIGBUS. This regression accord between rust stable version 1.43.0 and 1.44.0.

Is there anything else that i can provide?

debugger backtrace of the crash

(lldb) thread backtrace 
error: need to add support for DW_TAG_base_type '()' encoded with DW_ATE = 0x7, bit_size = 0
* thread #1, name = 'clacks', stop reason = signal SIGBUS: hardware error
  * frame #0: 0x00000000017922d0 clacks`elf_open_debugfile_by_debuglink + 736
    frame #1: 0x000000000178f0bf clacks`elf_add + 4831
    frame #2: 0x000000000179020f clacks`phdr_callback + 159
    frame #3: 0x0000000801822c7d ld-elf.so.1`dl_iterate_phdr(callback=(clacks`phdr_callback), param=0x00007fffffffb6a8) at rtld.c:3862:11
    frame #4: 0x000000000178dd55 clacks`__rdos_backtrace_initialize + 181
    frame #5: 0x000000000178d888 clacks`fileline_initialize + 520
    frame #6: 0x000000000178d908 clacks`__rdos_backtrace_syminfo + 40
    frame #7: 0x000000000178d470 clacks`backtrace::symbolize::libbacktrace::resolve::h3a61dabe094b7206 at libbacktrace.rs:469:9
    frame #8: 0x000000000178712f clacks`std::sys_common::backtrace::_print_fmt::_$u7b$$u7b$closure$u7d$$u7d$::h0677b5fd3830b218 [inlined] backtrace::symbolize::resolve_frame_unsynchronized::hef7e032eccfafb7f at mod.rs:178:5
    frame #9: 0x0000000001787119 clacks`std::sys_common::backtrace::_print_fmt::_$u7b$$u7b$closure$u7d$$u7d$::h0677b5fd3830b218 at backtrace.rs:85
    frame #10: 0x000000000178d143 clacks`backtrace::backtrace::libunwind::trace::trace_fn::h1daeb1a8d375438a [inlined] core::ops::function::impls::_$LT$impl$u20$core..ops..function..FnMut$LT$A$GT$$u20$for$u20$$RF$mut$u20$F$GT$::call_mut::hf60d687950595125 at function.rs:274:13
    frame #11: 0x000000000178d135 clacks`backtrace::backtrace::libunwind::trace::trace_fn::h1daeb1a8d375438a at libunwind.rs:98
    frame #12: 0x0000000801ed2385 libgcc_s.so.1`_Unwind_Backtrace(callback=(clacks`backtrace::backtrace::libunwind::trace::trace_fn::h1daeb1a8d375438a at libunwind.rs:88), ref=0x00007fffffffbbf8) at UnwindLevel1-gcc-ext.c:176:14
    frame #13: 0x0000000001786a5e clacks`_$LT$std..sys_common..backtrace.._print..DisplayBacktrace$u20$as$u20$core..fmt..Display$GT$::fmt::h0106ee1a603cd0b6 [inlined] backtrace::backtrace::libunwind::trace::he1e5a89a15469bef at libunwind.rs:86:5
    frame #14: 0x0000000001786a4a clacks`_$LT$std..sys_common..backtrace.._print..DisplayBacktrace$u20$as$u20$core..fmt..Display$GT$::fmt::h0106ee1a603cd0b6 [inlined] backtrace::backtrace::trace_unsynchronized::h05dfb6367fe3fba1 at mod.rs:66
    frame #15: 0x0000000001786a4a clacks`_$LT$std..sys_common..backtrace.._print..DisplayBacktrace$u20$as$u20$core..fmt..Display$GT$::fmt::h0106ee1a603cd0b6 [inlined] std::sys_common::backtrace::_print_fmt::hea538625ddec6cab at backtrace.rs:78
    frame #16: 0x0000000001786950 clacks`_$LT$std..sys_common..backtrace.._print..DisplayBacktrace$u20$as$u20$core..fmt..Display$GT$::fmt::h0106ee1a603cd0b6 at backtrace.rs:59
    frame #17: 0x00000000017aad6e clacks`core::fmt::write::h0f679dccd2cd93ed at mod.rs:1069:17
    frame #18: 0x0000000001784aa0 clacks`std::io::Write::write_fmt::h8e3cd870123d8365 at mod.rs:1504:15
    frame #19: 0x0000000001788bcd clacks`std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::h44b6384f03479f7d [inlined] std::sys_common::backtrace::_print::h4b166ab90c3c0d05 at backtrace.rs:62:5
    frame #20: 0x0000000001788b7c clacks`std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::h44b6384f03479f7d [inlined] std::sys_common::backtrace::print::h3c809c44af998731 at backtrace.rs:49
    frame #21: 0x0000000001788b6f clacks`std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::h44b6384f03479f7d at panicking.rs:198
    frame #22: 0x0000000001788899 clacks`std::panicking::default_hook::h40bc46c2d48b32f1 at panicking.rs:218:9
    frame #23: 0x0000000001789223 clacks`std::panicking::rust_panic_with_hook::h2373a0c0dc922484 at panicking.rs:511:17
    frame #24: 0x0000000001788e1c clacks`rust_begin_unwind at panicking.rs:419:5
    frame #25: 0x00000000017a94d0 clacks`core::panicking::panic_fmt::hc6bd8eedc6415ac1 at panicking.rs:111:14
    frame #26: 0x00000000017a9428 clacks`core::panicking::panic::h0897295336700263 at panicking.rs:54:5
    frame #27: 0x000000000135d0b8 clacks`core::option::Option$LT$T$GT$::unwrap::h9d2227361a73b518(self=Option<clacks::surface::Surface> @ 0x00007fffffffc820) at mod.rs:34:9
    frame #28: 0x00000000012ece70 clacks`clacks::main::_$u7b$$u7b$closure$u7d$$u7d$::hff644ca7ed799dc5((null)=0x0000000802e338e8, id=1, (null)=0x00007fffffffcef0, data=0x00007fffffffde50) at main.rs:30:13
    frame #29: 0x00000000012eb0de clacks`_$LT$core..cell..RefCell$LT$calloop..sources..Dispatcher$LT$Data$C$S$C$F$GT$$GT$$u20$as$u20$calloop..sources..EventDispatcher$LT$Data$GT$$GT$::process_events::_$u7b$$u7b$closure$u7d$$u7d$::h681570a23534e463(event=1, meta=0x00007fffffffcef0) at mod.rs:123:63
    frame #30: 0x0000000001357bda clacks`_$LT$calloop..sources..timer..Timer$LT$T$GT$$u20$as$u20$calloop..sources..EventSource$GT$::process_events::_$u7b$$u7b$closure$u7d$$u7d$::hf669e66fa4b13270((null)=<unavailable>, (null)=0x00007fffffffcda0) at timer.rs:133:21
    frame #31: 0x000000000130d500 clacks`_$LT$calloop..sources..ping..PingSource$u20$as$u20$calloop..sources..EventSource$GT$::process_events::_$u7b$$u7b$closure$u7d$$u7d$::h7307de8c6ce23969((null)=(readable = true, writable = false, error = false), (null)=0x0000000802e338f0) at ping.rs:82:21
    frame #32: 0x000000000132c630 clacks`_$LT$calloop..sources..generic..Generic$LT$F$GT$$u20$as$u20$calloop..sources..EventSource$GT$::process_events::h944c23cb209ef4ae(self=0x0000000802e338f0, readiness=(readable = true, writable = false, error = false), (null)=(id = 3, sub_id = 0), callback=closure-0 @ 0x00007fffffffcdf0) at generic.rs:72:9
    frame #33: 0x000000000130d329 clacks`_$LT$calloop..sources..ping..PingSource$u20$as$u20$calloop..sources..EventSource$GT$::process_events::haaebdc129a410678(self=0x0000000802e338f0, readiness=(readable = true, writable = false, error = false), token=(id = 3, sub_id = 0), callback=<unavailable>) at ping.rs:61:9
    frame #34: 0x0000000001357a7f clacks`_$LT$calloop..sources..timer..Timer$LT$T$GT$$u20$as$u20$calloop..sources..EventSource$GT$::process_events::hf09f7bc170b0563d(self=0x0000000802e338e8, readiness=(readable = true, writable = false, error = false), token=(id = 3, sub_id = 0), callback=closure-0 @ 0x00007fffffffcee0) at timer.rs:124:9
    frame #35: 0x00000000013357fa clacks`_$LT$core..cell..RefCell$LT$calloop..sources..Dispatcher$LT$Data$C$S$C$F$GT$$GT$$u20$as$u20$calloop..sources..EventDispatcher$LT$Data$GT$$GT$::process_events::h403953587e6701d2(self=0x0000000802e338e0, readiness=(readable = true, writable = false, error = false), token=(id = 3, sub_id = 0), data=0x00007fffffffde50) at mod.rs:123:9
    frame #36: 0x0000000001354068 clacks`calloop::loop_logic::EventLoop$LT$Data$GT$::dispatch_events::h613992ee94e72d1c(self=0x00007fffffffdcb0, timeout=Option<core::time::Duration> @ 0x00007fffffffd5b0, data=0x00007fffffffde50) at loop_logic.rs:268:17
    frame #37: 0x0000000001354ea0 clacks`calloop::loop_logic::EventLoop$LT$Data$GT$::dispatch::h3028638452db4e2d(self=0x00007fffffffdcb0, timeout=<unavailable>, data=0x00007fffffffde50) at loop_logic.rs:312:9
    frame #38: 0x000000000130c8f7 clacks`clacks::main::h267e80c9cfe3770b at main.rs:37:9
    frame #39: 0x000000000135323e clacks`std::rt::lang_start::_$u7b$$u7b$closure$u7d$$u7d$::hf558f6e5c37d6284 at rt.rs:67:34
    frame #40: 0x0000000001789662 clacks`std::rt::lang_start_internal::h718e9650bea5ab3e [inlined] std::rt::lang_start_internal::_$u7b$$u7b$closure$u7d$$u7d$::haf0a2cd12284040c at rt.rs:52:13
    frame #41: 0x0000000001789657 clacks`std::rt::lang_start_internal::h718e9650bea5ab3e [inlined] std::panicking::try::do_call::hbf7addf0f21316e7 at panicking.rs:331
    frame #42: 0x0000000001789657 clacks`std::rt::lang_start_internal::h718e9650bea5ab3e [inlined] std::panicking::try::h0c7bca60f996c7b7 at panicking.rs:274
    frame #43: 0x0000000001789657 clacks`std::rt::lang_start_internal::h718e9650bea5ab3e [inlined] std::panic::catch_unwind::h2eb406bb8ef4b25e at panic.rs:394
    frame #44: 0x0000000001789657 clacks`std::rt::lang_start_internal::h718e9650bea5ab3e at rt.rs:51
    frame #45: 0x0000000001353222 clacks`std::rt::lang_start::h76e9fa17a5ad4e33(main=(clacks`clacks::main::h267e80c9cfe3770b at main.rs:10), argc=1, argv=0x00007fffffffe4b0) at rt.rs:67:5
    frame #46: 0x000000000130ca1b clacks`main + 43
    frame #47: 0x00000000012ea7f2 clacks`_start(ap=<unavailable>, cleanup=<unavailable>) at crt1.c:76:7

[cemeyer]

I'm getting traces collected with nightly 1.49.0.20201121 on FreeBSD, but rust cannot resolve the addresses to symbols despite opt-level 0 and debug 2.

Edit: #78184 looks like my issue.

[asomers]

I can reproduce this problem with Rustc 1.46.0, but not 1.47.0. I guess it's already fixed.

[xanderio]

Just tested it. It works again