"attempt to subtract with overflow" printing empty object

[jyn514]

Steps to reproduce:

1. cargo install wrangler --version 1.19.5
2. cargo generate --git https://github.com/cloudflare/websocket-template --name websocket
3. cd websocket
4. Apply this diff:

diff --git a/websocket/index.js b/websocket/index.js
index 0221c8f..baafb4e 100644
--- a/websocket/index.js
+++ b/websocket/index.js
@@ -26,6 +26,7 @@ async function handleSession(websocket) {
 
 const websocketHandler = async request => {
   const upgradeHeader = request.headers.get("Upgrade")
+  console.log(request.headers);
   if (upgradeHeader !== "websocket") {
     return new Response("Expected websocket", { status: 400 })
   }
diff --git a/websocket/template.js b/websocket/template.js
index 9ed9b93..c34fb92 100644
--- a/websocket/template.js
+++ b/websocket/template.js
@@ -57,7 +57,7 @@ const template = `
   }
 
   const url = new URL(window.location)
-  url.protocol = "wss"
+  url.protocol = "ws"
   url.pathname = "/ws"
   websocket(url)
 

5. Navigate to http://127.0.0.1:8787/.

chrome_devtools_rs will panic:

   2: core::panicking::panic
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/panicking.rs:50:5
   3: <chrome_devtools::domain::runtime::type::remote_object::type::object::object_preview::ObjectPreview as core::fmt::Display>::fmt
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/chrome-devtools-rs-0.0.0-alpha.3/src/domain/runtime/type/remote_object/type/object/object_preview/mod.rs:89:38
   4: <T as alloc::string::ToString>::to_string
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/alloc/src/string.rs:2382:9
   5: chrome_devtools::domain::runtime::type::remote_object::RemoteObject::display_object
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/chrome-devtools-rs-0.0.0-alpha.3/src/domain/runtime/type/remote_object/mod.rs:54:13
   6: <chrome_devtools::domain::runtime::type::remote_object::RemoteObject as core::fmt::Display>::fmt
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/chrome-devtools-rs-0.0.0-alpha.3/src/domain/runtime/type/remote_object/mod.rs:102:29
   7: <&T as core::fmt::Display>::fmt
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:2031:62
   8: core::fmt::write
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:1110:17
   9: core::fmt::Formatter::write_fmt
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:1556:9
  10: <chrome_devtools::domain::runtime::event::console_api_called::Event as core::fmt::Display>::fmt
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/chrome-devtools-rs-0.0.0-alpha.3/src/domain/runtime/event/console_api_called.rs:22:13
  11: <&T as core::fmt::Display>::fmt
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:2031:62
  12: core::fmt::write
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:1110:17
  13: core::fmt::Formatter::write_fmt
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/fmt/mod.rs:1556:9
  14: <chrome_devtools::domain::runtime::event::Event as core::fmt::Display>::fmt
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/chrome-devtools-rs-0.0.0-alpha.3/src/domain/runtime/event/mod.rs:39:47
  15: <T as alloc::string::ToString>::to_string
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/alloc/src/string.rs:2382:9
  16: wrangler::commands::dev::socket::print_ws_messages::{{closure}}
             at /home/jnelson/src/wrangler/src/commands/dev/socket.rs:400:44
  17: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
             at /rustc/a178d0322ce20e33eac124758e837cbd80a6f633/library/core/src/future/mod.rs:80:19
  18: <tokio::future::maybe_done::MaybeDone<Fut> as core::future::future::Future>::poll
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.13.0/src/future/maybe_done.rs:68:48
  19: wrangler::commands::dev::socket::listen::{{closure}}::{{closure}}
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.13.0/src/macros/try_join.rs:132:20
  20: <tokio::future::poll_fn::PollFn<F> as core::future::future::Future>::poll
             at /home/jnelson/.local/lib/cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.13.0/src/future/poll_fn.rs:38:9
  21: wrangler::commands::dev::socket::listen::{{closure}}
             at /home/jnelson/src/wrangler/src/commands/dev/socket.rs:132:16

[jyn514]

https://github.com/cloudflare/chrome-devtools-rs/blob/d8fdf820d5337df1586fa0ff89b2bf420172522f/src/domain/runtime/type/remote_object/type/object/object_preview/mod.rs#L89