Running feature specs hang forever

[fnordfish]

After upgrading from rspec(-rails) v3.6.1 to v3.7.1 my capybara feature specs will no longer run:

* Pruning Bundler environment
[32156] Puma starting in cluster mode...
[32156] * Version 3.10.0 (ruby 2.4.1-p111), codename: Russell's Teapot
[32156] * Min threads: 5, max threads: 5
[32156] * Environment: test
[32156] * Process workers: 1
[32156] * Phased restart available
[32156] * Listening on tcp://0.0.0.0:3000
[32156] Use Ctrl-C to stop
[32174] + Gemfile in context: /home/vagrant/myproject/Gemfile
warning: parser/current is loading parser/ruby24, which recognizes
warning: 2.4.0-compliant syntax, but you are running 2.4.1.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
[32156] - Worker 0 (pid: 32174) booted, phase: 0

It will just hang in there and I have to kill (^C) the process, on CI it will run into an timeout.

I'm running on:

• rails (5.1.4)
• capybara (2.15.4)
• capybara-selenium (0.0.6)
• selenium-webdriver (3.6.0)
• puma (3.10.0)
• rspec-support (3.7.0)
• rspec-core (3.7.0)
• rspec-expectations (3.7.0)
• rspec-mocks (3.7.0)
• rspec (3.7.0)
• rspec-rails (3.7.1)

[JonRowe]

You need to configure puma to run in single server mode for tests, this is part of the Rails system test setup. You'll need to set workers to 0 and threads to 0,1 see conversation on #1813

[fnordfish]

Thanks! Will try