1979728 - Errors from subprocess worker do not include the original stack

Status: RESOLVED FIXED

(Toolkit :: Async Tooling, task)

Description

[Rob Wu [:robwu]]

While working on bug 1979546, I noticed that runtime errors in the subprocess module do not include a stack trace of the true source of the error.

E.g. if I intentionally throw from here by calling a non-existing function throwMe();,

then the console (pasted from a xpcshell test) contains the following entries:

• [JavaScript Error: "uncaught exception: Object" { file: "resource://gre/modules/subprocess/subprocess_common.sys.mjs" line: 199 }] (link to source)
• console.error: (new NotSupportedError("ClonedErrorHolder constructor: We can only clone DOM Exceptions and native JS Error objects", (void 0), 219)).
• [JavaScript Error: "throwMe not defined" {file: "resource://gre/modules/NativeMessaging.sys.mjs" line: 133 }] (link to source)

I think that this is happening because we turn an error into an object at https://searchfox.org/mozilla-central/rev/45aff2630491c295fc6c28198b629ff2de14e637/toolkit/modules/subprocess/subprocess_worker_common.js#206-215
Probably because the code predates support for errors in structured cloning.

Let's simplify the implementation so that true errors are reported, without strange bugs.

Comment 1

[Rob Wu [:robwu]]

Attachment: Bug 1979728 - Fix error propagation from subprocess worker

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/1237a547e337
https://hg.mozilla.org/integration/autoland/rev/6e316dc57c59
Fix error propagation from subprocess worker r=rpl

Comment 3

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/6e316dc57c59