1867758 - firefox-beta.desktop[3154]: [Parent 3154, IPC I/O Parent] WARNING: waitid failed pid:3255 errno:10: file /builds/worker/checkouts/gecko/ipc/chromium/src/base/process_util_posix.cc:244

Status: NEW

(Core :: IPC, defect, P2)

Description

[Maddi]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:121.0) Gecko/20100101 Firefox/121.0

Steps to reproduce:

Debian Bookworm Gnome Wayland with the following Firefox Beta / Nightly .deb package.
https://blog.nightly.mozilla.org/2023/10/30/introducing-mozillas-firefox-nightly-deb-packages-for-debian-based-linux-distributions/

Actual results:

I think it happens when I close Firefox.

Nov 22 16:33:58 firefox-nightly.desktop[8952]: [Parent 8952, IPC I/O Parent] WARNING: waitid failed pid:9456 errno:10: file /builds/worker/checkouts/gecko/ipc/chromium/src/base/process_util_posix.cc:244
...
Dez 01 12:14:07 firefox-beta.desktop[3154]: [Parent 3154, IPC I/O Parent] WARNING: waitid failed pid:3255 errno:10: file /builds/worker/checkouts/gecko/ipc/chromium/src/base/process_util_posix.cc:244

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::IPC' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

This is a known issue with the Nightly .deb package.

Longer explanation: .deb packages can be updated while the browser is running, and Nightly in particular has frequent updates, and normally Firefox can't start new child processes when the files on disk are from a different version. Thus, these packages enable the fork server, so that child processes are forked from a pre-launched process which already has the correct versions of the files opened/mapped. But, this is experimental and there are some relatively minor things that need to be fixed, and this is one of them.

We could suppress this warning when the fork server is enabled, because in that case we expect to get ECHILD when the parent process tries to waitid “child” processes that are actually grandchildren, but bug 1752638 will take care of the underlying issue.