Weird behaviour of the flaky test

[utkarsh2102]

Hello,

Thanks for your work and effort in maintaining http in such an awesome way! ❤️

However, this test:

http/spec/support/http_handling_shared.rb

Lines 47 to 49 in dbc73e3

	it "times out", :flaky do
	expect { response }.to raise_error(HTTP::TimeoutError, /Read/i)
	end

seems to be showing a weird behavior.

This test works fine, without any problems (as it should) when tried in an LXC or a docker container.
However, when tried in a VM or in Qemu, this fails with the following (relevant) logs:

Failures:

  1) HTTP::Client with a per operation timeout read of 0 times out
     Failure/Error: expect { response }.to raise_error(HTTP::TimeoutError, /Read/i)
       expected HTTP::TimeoutError with message matching /Read/i but nothing was raised
     Shared Example Group: "HTTP handling" called from ./spec/lib/http/client_spec.rb:284
     # /usr/share/rubygems-integration/all/gems/rspec-support-3.9.2/lib/rspec/support.rb:97:in `block in <module:Support>'
     # /usr/share/rubygems-integration/all/gems/rspec-support-3.9.2/lib/rspec/support.rb:106:in `notify_failure'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/fail_with.rb:35:in `fail_with'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/handler.rb:40:in `handle_failure'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/handler.rb:50:in `block in handle_matcher'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/handler.rb:27:in `with_matcher'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/handler.rb:48:in `handle_matcher'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/expectation_target.rb:65:in `to'
     # /usr/share/rubygems-integration/all/gems/rspec-expectations-3.9.0/lib/rspec/expectations/expectation_target.rb:101:in `to'
     # ./spec/support/http_handling_shared.rb:48:in `block (5 levels) in <top (required)>'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:257:in `instance_exec'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:257:in `block in run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:503:in `block in with_around_and_singleton_context_hooks'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:460:in `block in with_around_example_hooks'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/hooks.rb:472:in `block in run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/hooks.rb:610:in `run_around_example_hooks_for'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/hooks.rb:472:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:460:in `with_around_example_hooks'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:503:in `with_around_and_singleton_context_hooks'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example.rb:254:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:633:in `block in run_examples'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:629:in `map'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:629:in `run_examples'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:595:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `block in run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `map'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `block in run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `map'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `block in run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `map'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/example_group.rb:596:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:121:in `block (3 levels) in run_specs'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:121:in `map'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:121:in `block (2 levels) in run_specs'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/configuration.rb:2031:in `with_suite_hooks'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:116:in `block in run_specs'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/reporter.rb:74:in `report'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:115:in `run_specs'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:89:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:71:in `run'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/lib/rspec/core/runner.rb:45:in `invoke'
     # /usr/share/rubygems-integration/all/gems/rspec-core-3.9.1/exe/rspec:4:in `<main>'

Complete logs when tried in Qemu: https://paste.ubuntu.com/p/4rHT2kYyBH/
Complete logs when being tested in a VM: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/amd64/r/ruby-http/20200629_203732_72902@/log.gz

Personally, I have no idea what's going wrong or what might patch this.
Therefore, asking here since you'd be knowing what's (and why is it) happening!?