nvim_get_proc_children() may not return all child processes

[altermo]

Problem

nvim_get_proc_children() uses /proc/pid/task/tid/children on Linux systems (most of the time) which sometimes does not contain all child processes.

Steps to reproduce

(In this example firefox is used because I couldn't figure out how to create my own binary that would break it)

echo "
vim.system{'firefox','-P'}
vim.uv.sleep(1000)
local pid=assert(tonumber(vim.iter(vim.split(vim.system{'pgrep','firefox'}:wait().stdout,'\n',{trimempty=true})):nth(-1)))
vim.print('Child processes: '..vim.inspect(vim._os_proc_children(pid)))
vim.print('nvim_get_proc_children: '..vim.inspect(vim.api.nvim_get_proc_children(pid)))
"|nvim -l -

Expected behavior

Make nvim_get_proc_children() return all child processes.

Neovim version (nvim -v)

v0.10.0-dev-c795835

Vim (not Nvim) behaves the same?

N/A

Operating system/version

linux 6.8.9-arch1-2

Terminal name/version

kitty 0.33.1

$TERM environment variable

xterm-kitty

Installation

build from repo

[justinmk]

/proc/pid/task/tid/children on Linux systems (most of the time) which sometimes does not contain all child processes.

So this is a Linux bug ? :) What is the alternative?