Capybara.. launching browser failing saying nodename nor servname provided, or not known

Question

I am running capybara2.10 with ruby 2.4.1. browser launching is failing throwing error..

/Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/common/platform.rb:178:in `getaddrinfo': getaddrinfo: nodename nor servname provided, or not known (SocketError)
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/common/platform.rb:178:in `localhost'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/common/service.rb:48:in `initialize'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/firefox/marionette/driver.rb:41:in `new'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/firefox/marionette/driver.rb:41:in `initialize'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/firefox/driver.rb:31:in `new'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/firefox/driver.rb:31:in `new'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver/common/driver.rb:52:in `for'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/selenium-webdriver-3.9.0/lib/selenium/webdriver.rb:84:in `for'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/capybara-2.18.0/lib/capybara/selenium/driver.rb:23:in `browser'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/capybara-2.18.0/lib/capybara/selenium/driver.rb:49:in `visit'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/capybara-2.18.0/lib/capybara/session.rb:274:in `visit'
    from /Users/<user>/Documents/<project>/vendor/bundle/gems/capybara-2.18.0/lib/capybara/dsl.rb:50:in `block (2 levels) in <module:DSL>'
    from /Users/<user>/Documents/<project>/features/step_definitions/test1.rb:23:in `<top (required)>'
    from -e:1:in `load'
    from -e:1:in `<main>'

Please help me to resolve this. Thank you.

Answer 1

Adding this 127.0.0.1 localhost in /etc/hosts is fixed the issue