[🐛 Bug]: Trying to terminate a ChildProcess that's already gone

[johlym]

What happened?

Using selenium-webdriver 4.25.0 or 4.26.0, Ruby 3.2.2 (or 3.3.5), and teaspon 1.4.0, we run into an issue where Webdriver tries to terminate its child process and throws an exception because the process doesn't exist. (see log output)

This is slightly different than, but seemingly related to #14032, in that ErrNo::ERSCH is thrown, rather than Errno::ECHILD in #14032.

We are able to work around this by creating a small money patch to override the terminate method (as an initializer since this is a Rails app):

# config/initializers/selenium_monkey_patch.rb

require 'selenium-webdriver' # Ensure selenium-webdriver is loaded

module Selenium
  module WebDriver
    class ChildProcess
      # Monkey patch the terminate method to rescue from the browser
      # process already having been terminated for hashtag reasons.
      # Is similar but not exactly the same as the problem described
      # in https://github.com/SeleniumHQ/selenium/issues/14032
      def terminate(pid)
        Process.kill('SIGTERM', pid)
      rescue Errno::ECHILD, Errno::ESRCH
        # Process is already dead, no action needed
        p "MONKEYPATCH: Process is already dead, no action needed"
        p "MONKEYPATCH: Don't leave me this way!"
      end
    end
  end
end

How can we reproduce the issue?

Run `bundle exec teaspoon` under Ruby 3.2.2 or Ruby 3.3.5, with `selenium-webdriver` 4.25.0 or 4.26.0

Relevant log output

Teaspoon running default suite at http://127.0.0.1:43075/teaspoon/default
.........................

Finished in 0.03000 seconds
25 examples, 0 failures
bundler: failed to load command: teaspoon (/home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/bin/teaspoon)
/home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/child_process.rb:114:in `kill': No such process (Errno::ESRCH)
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/child_process.rb:114:in `terminate'
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/child_process.rb:68:in `stop'
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/service_manager.rb:110:in `stop_process'
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/service_manager.rb:71:in `stop'
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/service_manager.rb:53:in `block in start'
	from /home/runner/work/elements/elements/vendor/bundle/ruby/3.2.0/gems/selenium-webdriver-4.25.0/lib/selenium/webdriver/common/platform.rb:152:in `block in exit_hook'

### Operating System

macOS, Linux

### Selenium version

4.25.0

### What are the browser(s) and version(s) where you see this issue?

Headless chrome, firefox

### What are the browser driver(s) and version(s) where you see this issue?

latest as invoked by selenium-manager

### Are you using Selenium Grid?

n/a

[github-actions]

@johlym, thank you for creating this issue. We will troubleshoot it as soon as we can.

---

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