wrangler dev: panicked at 'Failed to connect to devtools instance'

Created on 19 Aug 2020 · 10Comments · Source: cloudflare/wrangler

🐛 Bug Report

Environment

operating system: Microsoft Windows [Version 10.0.18363.1016]
output of rustc -V: rustc 1.44.1 (c7087fe00 2020-06-17)
output of node -v: v14.5.0
output of wrangler -V: wrangler 1.10.3
contents of wrangler.toml

name = "name-dev"
type = "webpack"
webpack_config = "webpack.dev.js"
account_id = "id ahsjkdhalsdhalkjdh"
workers_dev = true
route = ""
zone_id = ""

[env.production]
name = "name"
webpack_config = "webpack.config.js"

Steps to reproduce

If I leave wrangler dev running for a long time sometimes this happens. It is unclear for me why. It may be my unstable internet connection, but still if so, I'd expect for wrangler to keep retrying until the connection is restored or something like that for a more graceful experience.

What did you expect to see?

What did you see instead?

message 'Nieznany host' means 'unknown host'

thread 'tokio-runtime-worker' panicked at 'Failed to connect to devtools instance: Io(Os { code: 11001, kind: Other, message: "Nieznany host." })', C:\Users\Admin\.cargo\registry\src\github.com-1ecc6299db9ec823\wrangler-1.10.3\src\commands\dev\socket.rs:29:30
stack backtrace:
   0: backtrace::backtrace::dbghelp::trace
             at C:\Users\VssAdministrator\.cargo\registry\src\github.com-1ecc6299db9ec823\backtrace-0.3.46\src\backtrace/dbghelp.rs:88
   1: backtrace::backtrace::trace_unsynchronized
             at C:\Users\VssAdministrator\.cargo\registry\src\github.com-1ecc6299db9ec823\backtrace-0.3.46\src\backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src\libstd\sys_common/backtrace.rs:78
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src\libstd\sys_common/backtrace.rs:59
   4: core::fmt::write
             at src\libcore\fmt/mod.rs:1069
   5: std::io::Write::write_fmt
             at src\libstd\io/mod.rs:1504
   6: std::sys_common::backtrace::_print
             at src\libstd\sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src\libstd\sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src\libstd/panicking.rs:198
   9: std::panicking::default_hook
             at src\libstd/panicking.rs:218
  10: std::panicking::rust_panic_with_hook
             at src\libstd/panicking.rs:511
  11: rust_begin_unwind
             at src\libstd/panicking.rs:419
  12: core::panicking::panic_fmt
             at src\libcore/panicking.rs:111
  13: core::option::expect_none_failed
             at src\libcore/option.rs:1268
  14: wrangler::commands::dev::socket::listen::{{closure}}
  15: tokio::runtime::task::core::Core<T,S>::poll
  16: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  17: tokio::runtime::task::harness::Harness<T,S>::poll
  18: std::thread::local::LocalKey<T>::with
  19: tokio::runtime::thread_pool::worker::Context::run_task
  20: tokio::runtime::thread_pool::worker::Context::run
  21: tokio::macros::scoped_tls::ScopedKey<T>::set
  22: tokio::runtime::thread_pool::worker::run
  23: <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll
  24: tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
  25: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  26: tokio::runtime::task::harness::Harness<T,S>::poll
  27: tokio::runtime::blocking::pool::Inner::run
  28: tokio::runtime::context::enter
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Error: panic
   0: backtrace::backtrace::trace
   1: backtrace::capture::Backtrace::new_unresolved
   2: failure::backtrace::internal::InternalBacktrace::new
   3: <failure::backtrace::Backtrace as core::default::Default>::default
   4: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   5: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
   6: <tokio::future::poll_fn::PollFn<F> as core::future::future::Future>::poll
   7: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   8: std::thread::local::LocalKey<T>::with
   9: tokio::runtime::enter::Enter::block_on
  10: tokio::runtime::context::enter
  11: wrangler::commands::dev::gcs::dev
  12: wrangler::commands::dev::dev
  13: wrangler::run
  14: wrangler::main
  15: std::rt::lang_start::{{closure}}
  16: std::rt::lang_start_internal::{{closure}}
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/rt.rs:52
      std::panicking::try::do_call
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panicking.rs:331
      std::panicking::try
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panicking.rs:274
      std::panic::catch_unwind
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panic.rs:394
      std::rt::lang_start_internal
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/rt.rs:51
  17: main
  18: __tmainCRTStartup
  19: mainCRTStartup
  20: <unknown>
  21: <unknown>

With FULL backtrace, this is right after starting the command, and my internet connection seemed fine.

 Built successfully, built project size is 47 KiB.
 Listening on http://127.0.0.1:8787
 Detected changes...
 Ignoring stale first change
thread 'tokio-runtime-worker' panicked at 'Failed to connect to devtools instance: Io(Os { code: 11001, kind: Other, message: "Nieznany host." })', C:\Users\Admin\.cargo\registry\src\github.com-1ecc6299db9ec823\wrangler-1.10.3\src\commands\dev\socket.rs:29:30
stack backtrace:
   0:           0xf9f09b - backtrace::backtrace::dbghelp::trace::h39d3b7e54c98bfeb
                               at C:\Users\VssAdministrator\.cargo\registry\src\github.com-1ecc6299db9ec823\backtrace-0.3.46\src\backtrace/dbghelp.rs:88
   1:           0xf9f09b - backtrace::backtrace::trace_unsynchronized::hece815955ee584f5
                               at C:\Users\VssAdministrator\.cargo\registry\src\github.com-1ecc6299db9ec823\backtrace-0.3.46\src\backtrace/mod.rs:66
   2:           0xf9f09b - std::sys_common::backtrace::_print_fmt::h6329aad3c4e33b91
                               at src\libstd\sys_common/backtrace.rs:78
   3:           0xf9f09b - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h70d081ab68653703
                               at src\libstd\sys_common/backtrace.rs:59
   4:           0xfcb16b - core::fmt::write::h8208faec44da3f47
                               at src\libcore\fmt/mod.rs:1069
   5:           0xf8fde5 - std::io::Write::write_fmt::hf1bea4fcea6e8faf
                               at src\libstd\io/mod.rs:1504
   6:           0xfa38e1 - std::sys_common::backtrace::_print::h8d3665e9fac8ab4d
                               at src\libstd\sys_common/backtrace.rs:62
   7:           0xfa38e1 - std::sys_common::backtrace::print::h2c7cda1ee814fd49
                               at src\libstd\sys_common/backtrace.rs:49
   8:           0xfa38e1 - std::panicking::default_hook::{{closure}}::h539aa264476ab506
                               at src\libstd/panicking.rs:198
   9:           0xfa3556 - std::panicking::default_hook::h375187d8fe0b473b
                               at src\libstd/panicking.rs:218
  10:           0xfa3f54 - std::panicking::rust_panic_with_hook::h9fee4158d03ea72d
                               at src\libstd/panicking.rs:511
  11:           0xfa3b74 - rust_begin_unwind
                               at src\libstd/panicking.rs:419
  12:           0xfc7bc0 - core::panicking::panic_fmt::hf5f4b1ece6e49331
                               at src\libcore/panicking.rs:111
  13:           0xfc7823 - core::option::expect_none_failed::h75bc420e8ab0df51
                               at src\libcore/option.rs:1268
  14:           0x4ccf76 - wrangler::commands::dev::socket::listen::{{closure}}::hfdf2ad3c55940ba5
  15:           0x5af13a - tokio::runtime::task::core::Core<T,S>::poll::h1ebd5ece289a12d4
  16:           0x43a81c - <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::hc58bb649371093d8
  17:           0x77ad3c - tokio::runtime::task::harness::Harness<T,S>::poll::h668016d271f88332
  18:           0xe3c1c6 - std::thread::local::LocalKey<T>::with::h952b3184d8beb16a
  19:           0xe5cabe - tokio::runtime::thread_pool::worker::Context::run_task::h1bbbedc55b655e66
  20:           0xe5bd97 - tokio::runtime::thread_pool::worker::Context::run::h2aa2d45d9121b377
  21:           0xe5f1d1 - tokio::macros::scoped_tls::ScopedKey<T>::set::hafb773f2a9153810
  22:           0xe5bbda - tokio::runtime::thread_pool::worker::run::h10946eaecda27a65
  23:           0xe80998 - <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll::hf8173ffeea7d33a2
  24:           0xe60dce - tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut::h3c4ca295d265cc4b
  25:           0xe8866f - <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h47d01caa69d0d9e0
  26:           0xe6c130 - tokio::runtime::task::harness::Harness<T,S>::poll::h63b08ffdd2f5e92a
  27:           0xe545e6 - tokio::runtime::blocking::pool::Inner::run::h55a8ac38df4dce14
  28:           0xe7bc8c - tokio::runtime::context::enter::h2512afe60ecb13d3
  29:           0xe648e4 - std::sys_common::backtrace::__rust_begin_short_backtrace::h940f9c82de61e060
  30:           0xe51d52 - core::ops::function::FnOnce::call_once{{vtable.shim}}::hdac0371e2a282b0b
  31:           0xfb2920 - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h128ecbf3019fe93f
                               at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\src\liballoc/boxed.rs:1008
  32:           0xfb2920 - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h51262c82125a675c
                               at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\src\liballoc/boxed.rs:1008
  33:           0xfb2920 - std::sys::windows::thread::Thread::new::thread_start::ha62450f1da1b59c3
                               at src\libstd\sys\windows/thread.rs:56
  34:     0x7ffd6df47bd4 - _report_error
  35:     0x7ffd6ea0ce51 - _report_error
Error: panic
   0: backtrace::backtrace::trace
   1: backtrace::capture::Backtrace::new_unresolved
   2: failure::backtrace::internal::InternalBacktrace::new
   3: <failure::backtrace::Backtrace as core::default::Default>::default
   4: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   5: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
   6: <tokio::future::poll_fn::PollFn<F> as core::future::future::Future>::poll
   7: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   8: std::thread::local::LocalKey<T>::with
   9: tokio::runtime::enter::Enter::block_on
  10: tokio::runtime::context::enter
  11: wrangler::commands::dev::gcs::dev
  12: wrangler::commands::dev::dev
  13: wrangler::run
  14: wrangler::main
  15: std::rt::lang_start::{{closure}}
  16: std::rt::lang_start_internal::{{closure}}
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/rt.rs:52
      std::panicking::try::do_call
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panicking.rs:331
      std::panicking::try
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panicking.rs:274
      std::panic::catch_unwind
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/panic.rs:394
      std::rt::lang_start_internal
             at /rustc/c7087fe00d2ba919df1d813c040a5d47e43b0fe7\/src\libstd/rt.rs:51
  17: main
  18: __tmainCRTStartup
  19: mainCRTStartup
  20: <unknown>
  21: <unknown>
````

Another one:

bug subject - wrangler dev user report

Source

JakubKoralewski

👍6

Most helpful comment

Same problem for me on macOS 10.15, this Issue is open since August, can't someone finally fix this? It's super annoying. 😩

tsndr on 9 Nov 2020

👍2

All 10 comments

I have the same issue:

$ wrangler -V
👷 ✨  wrangler 1.11.0

$ node -v
v14.8.0

$ rustc -V
rustc 1.47.0-nightly (32c654a97 2020-08-19)

$ RUST_BACKTRACE=1 wrangler dev
💁  JavaScript project found. Skipping unnecessary build!
💁  watching "./"
thread 'tokio-runtime-worker' panicked at 'Failed to connect to devtools instance: Http(400)', src/commands/dev/socket.rs:26:30
stack backtrace:
👂  Listening on http://127.0.0.1:8787
   0: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
   1: core::fmt::write
   2: std::io::Write::write_fmt
   3: std::panicking::default_hook::{{closure}}
   4: std::panicking::default_hook
   5: std::panicking::rust_panic_with_hook
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
   9: wrangler::commands::dev::socket::listen::{{closure}}
  10: tokio::runtime::task::core::Core<T,S>::poll
  11: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  12: tokio::runtime::task::harness::Harness<T,S>::poll
  13: std::thread::local::LocalKey<T>::with
  14: tokio::runtime::thread_pool::worker::Context::run_task
  15: tokio::runtime::thread_pool::worker::Context::run
  16: tokio::macros::scoped_tls::ScopedKey<T>::set
  17: tokio::runtime::thread_pool::worker::run
  18: tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
  19: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  20: tokio::runtime::task::harness::Harness<T,S>::poll
  21: tokio::runtime::blocking::pool::Inner::run
  22: tokio::runtime::context::enter
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Error: panic
   0: backtrace::backtrace::trace
   1: backtrace::capture::Backtrace::new_unresolved
   2: failure::backtrace::internal::InternalBacktrace::new
   3: failure::backtrace::Backtrace::new
   4: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   5: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
   6: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   7: std::thread::local::LocalKey<T>::with
   8: tokio::runtime::enter::Enter::block_on
   9: tokio::runtime::thread_pool::ThreadPool::block_on
  10: tokio::runtime::context::enter
  11: wrangler::commands::dev::edge::dev
  12: wrangler::commands::dev::dev
  13: wrangler::run
  14: wrangler::main
  15: std::rt::lang_start::{{closure}}
  16: std::rt::lang_start_internal
  17: _main

publicarray on 23 Aug 2020

This is now happening every minute. I have now observed my WiFi icon flicker into no internet connection icon in my Windows Taskbar right as the error happened. Adding some e2e tests with unstable internet connection would be a great first step in diagnosing the problem.

JakubKoralewski on 27 Aug 2020

Yea I have this very often as well. Did not happen as much with old wrangler version: v1.10.x

dgitq on 11 Sep 2020

👍1

I'm having this problem on Linux (Ubuntu) on 1.11.0, if I downgrade to 1.10.0 it works perfectly.

davidbarratt on 11 Oct 2020

Same problem for me on macOS 10.15, this Issue is open since August, can't someone finally fix this? It's super annoying. 😩

tsndr on 9 Nov 2020

👍2

Same problem with different version and stack

Is there some temp workaround for it. Can't start developing it at all currently

$ cat /etc/os-release

NAME="openSUSE Tumbleweed"
VERSION_ID="20201119"
...

$ wrangler --version

👷 ✨  wrangler 1.12.2

thread 'tokio-runtime-worker' panicked at 'Failed to connect to devtools instance: Http(500)', src/commands/dev/socket.rs:28:14
stack backtrace:
   0: rust_begin_unwind
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:475
   1: core::panicking::panic_fmt
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/panicking.rs:85
   2: core::option::expect_none_failed
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/option.rs:1221
   3: wrangler::commands::dev::socket::listen::{{closure}}
   4: tokio::runtime::task::core::Core<T,S>::poll
   5: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
   6: tokio::runtime::task::harness::Harness<T,S>::poll
   7: tokio::runtime::thread_pool::worker::Context::run_task
   8: tokio::runtime::thread_pool::worker::Context::run
   9: tokio::macros::scoped_tls::ScopedKey<T>::set
  10: tokio::runtime::thread_pool::worker::run
  11: tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut
  12: tokio::runtime::task::core::Core<T,S>::poll
  13: <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
  14: tokio::runtime::task::harness::Harness<T,S>::poll
  15: tokio::runtime::blocking::pool::Inner::run
  16: tokio::runtime::context::enter
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Error: panic
   0: failure::backtrace::internal::InternalBacktrace::new
   1: <failure::backtrace::Backtrace as core::default::Default>::default
   2: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   3: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
   4: <tokio::future::poll_fn::PollFn<F> as core::future::future::Future>::poll
   5: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   6: std::thread::local::LocalKey<T>::with
   7: tokio::runtime::enter::Enter::block_on
   8: tokio::runtime::thread_pool::ThreadPool::block_on
   9: tokio::runtime::context::enter
  10: wrangler::commands::dev::gcs::dev
  11: wrangler::commands::dev::dev
  12: wrangler::run
  13: wrangler::main
  14: std::sys_common::backtrace::__rust_begin_short_backtrace
  15: std::rt::lang_start::{{closure}}
  16: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/ops/function.rs:259:13
      std::panicking::try::do_call
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:373:40
      std::panicking::try
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:337:19
      std::panic::catch_unwind
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panic.rs:379:14
      std::rt::lang_start_internal
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/rt.rs:51:25
  17: main

$ RUST_BACKTRACE=full wrangler dev

Warning: webpack's output filename is being renamed to worker.js because of requirements from the Workers runtime
unauthenticated

  ╭─────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
  │                                                                                                                 │
  │                               You have not provided your Cloudflare credentials.                                │
  │                                                                                                                 │
  │                            Please run `wrangler login`, `wrangler config`, or visit                             │
  │      https://developers.cloudflare.com/workers/tooling/wrangler/configuration/#using-environment-variables      │
  │                             for info on authenticating with environment variables.                              │
  │                                                                                                                 │
  ╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

💁  Running preview without authentication.
👂  Listening on http://127.0.0.1:8787
Warning: webpack's output filename is being renamed to worker.js because of requirements from the Workers runtime
🌀  Detected changes...
💁  Ignoring stale first change
thread 'tokio-runtime-worker' panicked at 'Failed to connect to devtools instance: Http(500)', src/commands/dev/socket.rs:28:14
stack backtrace:
   0:           0xed5400 - std::backtrace_rs::backtrace::libunwind::trace::he7dddadb03f61005
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/../../backtrace/src/backtrace/libunwind.rs:96
   1:           0xed5400 - std::backtrace_rs::backtrace::trace_unsynchronized::h1ceb1f2ab6cd4ca2
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/../../backtrace/src/backtrace/mod.rs:66
   2:           0xed5400 - std::sys_common::backtrace::_print_fmt::hdb0b27a9509ec894
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys_common/backtrace.rs:79
   3:           0xed5400 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hc4df5611fab8201a
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys_common/backtrace.rs:58
   4:           0xf1d6fc - core::fmt::write::habf2dbeb36546e2f
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/fmt/mod.rs:1082
   5:           0xecd287 - std::io::Write::write_fmt::hc70a74b259f58998
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/io/mod.rs:1514
   6:           0xed7c80 - std::sys_common::backtrace::_print::h266c2be06be6d066
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys_common/backtrace.rs:61
   7:           0xed7c80 - std::sys_common::backtrace::print::h23b774f8e5a41ff8
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys_common/backtrace.rs:48
   8:           0xed7c80 - std::panicking::default_hook::{{closure}}::h29a9a8f8e81c7702
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:200
   9:           0xed79cc - std::panicking::default_hook::h7d87e53c58aa24f6
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:219
  10:           0xed82e3 - std::panicking::rust_panic_with_hook::hb21f7ba598c369dc
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:569
  11:           0xed7eb9 - std::panicking::begin_panic_handler::{{closure}}::h39563748bfa0aad5
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:476
  12:           0xed588c - std::sys_common::backtrace::__rust_end_short_backtrace::hc748610f44302c03
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys_common/backtrace.rs:153
  13:           0xed7e79 - rust_begin_unwind
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:475
  14:           0xf1b2c1 - core::panicking::panic_fmt::h7fb23425bb96f2aa
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/panicking.rs:85
  15:           0xf1b0e3 - core::option::expect_none_failed::h334786424516dc51
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/option.rs:1221
  16:           0x740540 - wrangler::commands::dev::socket::listen::{{closure}}::h967b15edf92a1883
  17:           0x450d40 - tokio::runtime::task::core::Core<T,S>::poll::h7c451dde7e6035d7
  18:           0x5f8009 - <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::hc7b62de318196897
  19:           0x7d3ff9 - tokio::runtime::task::harness::Harness<T,S>::poll::h9aca7a07557ee577
  20:           0xe945ad - tokio::runtime::thread_pool::worker::Context::run_task::h7bc10754970be0f8
  21:           0xe93cfe - tokio::runtime::thread_pool::worker::Context::run::hc50c6c1c91860281
  22:           0xe9ec13 - tokio::macros::scoped_tls::ScopedKey<T>::set::hec0755e460b235f6
  23:           0xe937f6 - tokio::runtime::thread_pool::worker::run::hc040b4ba703102d7
  24:           0xe9a8f4 - tokio::loom::std::unsafe_cell::UnsafeCell<T>::with_mut::hc831298f4ece7e2b
  25:           0xe88063 - tokio::runtime::task::core::Core<T,S>::poll::h5d525ff395b574d1
  26:           0xe8b213 - <std::panic::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::hae77dc012d284325
  27:           0xe9ff03 - tokio::runtime::task::harness::Harness<T,S>::poll::h3f297c178b7fd9d9
  28:           0xe92651 - tokio::runtime::blocking::pool::Inner::run::ha6b16e08d1231d3c
  29:           0xe87c58 - tokio::runtime::context::enter::h59af7bf56324cced
  30:           0xe8b34f - std::sys_common::backtrace::__rust_begin_short_backtrace::h09c721c7bc3afebc
  31:           0xe7a9a2 - core::ops::function::FnOnce::call_once{{vtable.shim}}::h17a7241b5fe7fe71
  32:           0xee113a - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::hb2f6edb25a56287d
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/alloc/src/boxed.rs:1042
  33:           0xee113a - <alloc::boxed::Box<F> as core::ops::function::FnOnce<A>>::call_once::h9d1295ce9c43ed06
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/alloc/src/boxed.rs:1042
  34:           0xee113a - std::sys::unix::thread::Thread::new::thread_start::h92f94effbbdd33e1
                               at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/sys/unix/thread.rs:87
Error: panic
   0: failure::backtrace::internal::InternalBacktrace::new
   1: <failure::backtrace::Backtrace as core::default::Default>::default
   2: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   3: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
   4: <tokio::future::poll_fn::PollFn<F> as core::future::future::Future>::poll
   5: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
   6: std::thread::local::LocalKey<T>::with
   7: tokio::runtime::enter::Enter::block_on
   8: tokio::runtime::thread_pool::ThreadPool::block_on
   9: tokio::runtime::context::enter
  10: wrangler::commands::dev::gcs::dev
  11: wrangler::commands::dev::dev
  12: wrangler::run
  13: wrangler::main
  14: std::sys_common::backtrace::__rust_begin_short_backtrace
  15: std::rt::lang_start::{{closure}}
  16: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/core/src/ops/function.rs:259:13
      std::panicking::try::do_call
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:373:40
      std::panicking::try
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panicking.rs:337:19
      std::panic::catch_unwind
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/panic.rs:379:14
      std::rt::lang_start_internal
             at /rustc/18bf6b4f01a6feaf7259ba7cdae58031af1b7b39/library/std/src/rt.rs:51:25
  17: main