Rust built-in stack traces don't work on Helios

[davepacheco]

dap@helios ~ $ cargo new stack-test
     Created binary (application) `stack-test` package
dap@helios ~ $ cd !$
cd stack-test
dap@helios stack-test $ vim src/main.rs 
dap@helios stack-test $ cat src/main.rs 
fn main() {
    panic!("uh oh!");
}
dap@helios stack-test $ uname -a
SunOS helios 5.11 helios-1.0.20336 i86pc i386 i86pc
dap@helios stack-test $ cargo version
cargo 1.50.0 (f04e7fab7 2021-02-04)
dap@helios stack-test $ cargo run 
   Compiling stack-test v0.1.0 (/home/dap/stack-test)
    Finished dev [unoptimized + debuginfo] target(s) in 2.36s
     Running `target/debug/stack-test`
thread 'main' panicked at 'uh oh!', src/main.rs:2:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
dap@helios stack-test $ RUST_BACKTRACE=1 cargo run 
    Finished dev [unoptimized + debuginfo] target(s) in 0.03s
     Running `target/debug/stack-test`
thread 'main' panicked at 'uh oh!', src/main.rs:2:5
stack backtrace:
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
dap@helios stack-test $ RUST_BACKTRACE=full cargo run 
    Finished dev [unoptimized + debuginfo] target(s) in 0.03s
     Running `target/debug/stack-test`
thread 'main' panicked at 'uh oh!', src/main.rs:2:5
stack backtrace:
   0:           0x4c56ce - <unknown>
   1:           0x530c7d - <unknown>
   2:           0x4b759e - <unknown>
   3:           0x4c90f9 - <unknown>
   4:           0x4c8c9d - <unknown>
   5:           0x4c9943 - <unknown>
   6:           0x48bef7 - <unknown>
   7:           0x48ba48 - <unknown>
   8:           0x48be57 - <unknown>
   9:           0x48c58c - <unknown>
  10:           0x48c4ae - <unknown>
  11:           0x48ba81 - <unknown>
  12:           0x48ba04 - <unknown>
  13:           0x4c9cf3 - <unknown>
  14:           0x48b9e1 - <unknown>
  15:           0x48c5bb - <unknown>
  16:           0x48b2d7 - <unknown>
  17:           0x48b238 - <unknown>
dap@helios stack-test $ 

@jclulow reports that he has seen these stack traces work on illumos before. So I went back as far as I could with rustup, which was 1.47, but it's broken in 1.47 as well. I know there were unofficial builds before then.

[jclulow]

I believe this was sorted out by some work on the backtrace crate in rust-lang/backtrace-rs#416 and subsequently included in the Rust toolchain via rust-lang/rust#84563. The other part of this was rust-lang/rust#84254 which has also been in for a while, so I think we can close this out!