Panic occurs when running `deno test | hoge

[skanehira]

Summary

Panic occurs when running deno test | hoge
It seems that panic occurs when using a non-existent command with pipe.

root@c2814216bc11:/sandbox# cat hoge_test.ts 
Deno.test("hoge", () => {})
root@c2814216bc11:/sandbox# RUST_BACKTRACE=full deno test | hoge
bash: hoge: command not found

============================================================
Deno has panicked. This is a bug in Deno. Please report this
at https://github.com/denoland/deno/issues/new.
If you can reliably reproduce this panic, include the
reproduction steps and re-run with the RUST_BACKTRACE=1 env
var set and include the backtrace in your report.

Platform: linux aarch64
Version: 1.25.1
Args: ["deno", "test"]

thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', library/std/src/io/stdio.rs:1015:9
stack backtrace:
   0:     0xaaaad6e5bff4 - std::backtrace_rs::backtrace::libunwind::trace::hdaf7b926686b76e5
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0xaaaad6e5bff4 - std::backtrace_rs::backtrace::trace_unsynchronized::h24b637dca55f9a5e
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0xaaaad6e5bff4 - std::sys_common::backtrace::_print_fmt::h4cb8409104309785
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:66:5
   3:     0xaaaad6e5bff4 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc4ec9cb9b20b5a7b
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:45:22
   4:     0xaaaad6667994 - core::fmt::write::h2322d71f3fb268fc
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/fmt/mod.rs:1197:17
   5:     0xaaaad6e3241c - std::io::Write::write_fmt::hc0c6b55df7cbd64b
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/io/mod.rs:1672:15
   6:     0xaaaad6e5df20 - std::sys_common::backtrace::_print::h446ed48475d9d586
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:48:5
   7:     0xaaaad6e5df20 - std::sys_common::backtrace::print::h9b9a1d50fa9ea120
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:35:9
   8:     0xaaaad6e5df20 - std::panicking::default_hook::{{closure}}::ha6c2222df3379e34
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:295:22
   9:     0xaaaad6e5dbe0 - std::panicking::default_hook::hfce7a8f7bcbba82f
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:314:9
  10:     0xaaaad66165b0 - deno::setup_panic_hook::{{closure}}::h70f0e0e72ca716d3
  11:     0xaaaad6e5e978 - std::panicking::rust_panic_with_hook::h90a858afb3dbe829
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:702:17
  12:     0xaaaad6e5e7d8 - std::panicking::begin_panic_handler::{{closure}}::h882ab86c0d7c5158
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:588:13
  13:     0xaaaad6e5e754 - std::sys_common::backtrace::__rust_end_short_backtrace::hbcab7df1db34555f
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:138:18
  14:     0xaaaad6e5e720 - rust_begin_unwind
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:584:5
  15:     0xaaaad635fec0 - core::panicking::panic_fmt::h58c4ca31339ea3fd
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/panicking.rs:142:14
  16:     0xaaaad6e51e34 - std::io::stdio::print_to::h9bc1b47bf826d5bf
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/io/stdio.rs:1015:9
  17:     0xaaaad6e51e34 - std::io::stdio::_print::h289c5a7b1c4fbf2f
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/io/stdio.rs:1027:5
  18:     0xaaaad65a1d7c - deno::tools::test::test_specifiers::{{closure}}::{{closure}}::h5bc01f3ead2e432f
  19:     0xaaaad65a1894 - tokio::runtime::task::harness::poll_future::h27742c278ca015bf
  20:     0xaaaad65a4898 - tokio::runtime::task::raw::poll::hb015e049a96a5e42
  21:     0xaaaad63b7a9c - deno_runtime::tokio_util::run_local::h549c3a54c2cf7083
  22:     0xaaaad63b70a0 - deno::main::hab3a8044ad842722
  23:     0xaaaad63b6938 - std::sys_common::backtrace::__rust_begin_short_backtrace::h0fd13418802ddd8d
  24:     0xaaaad63b6c68 - main
  25:     0xffffb0d673fc - <unknown>
  26:     0xffffb0d674cc - __libc_start_main
  27:     0xaaaad63916e4 - <unknown>
root@c2814216bc11:/sandbox# 

[kitsonk]

It shouldn't panic, but obviously it isn't going to work.

[sigmaSd]

This doesn't affect deno test only but all deno commands, "fixing" this would require changing all print! to write! and handling all the errors, I think it's just not worth it.

The only improvement I can see is not printing that message on this kind of situation, but I'm not sure how would one detect this.

[sigmaSd]

On our custom panic hook, we can match on the panic message, and detect if its a broken pipe error and in that case write a better error

Do you think this is a reasonable approach ?

[sigmaSd]

The messages stability are not guaranteed by rust API as far as I know, but it should still mostly work, and if it doesn't it just shows the current behavior

[bartlomieju]

@sigmaSd could you open a PR that implements this solution?