When you run RSpec, you might see the following output:
$ bundle exec rspec
Randomized with seed 59799
............................................................................................Capybara starting Puma...
* Version 4.3.1 , codename: Mysterious Traveller
* Min threads: 0, max threads: 4
* Listening on tcp://127.0.0.1:42837
...................................................................
Capybara starting Puma is shown in the RSpec output.
Capybara starting Puma...
* Version 4.3.1 , codename: Mysterious Traveller
* Min threads: 0, max threads: 4
* Listening on tcp://127.0.0.1:42837
This is because Puma is started by Capybara when system test is invoked.
You can make it silent by setting. In your test helper, add the line:
Capybara.server = :puma, { Silent: true }
It means run puma server silently.
After this setting:
$ bundle exec rspec
Randomized with seed 45766
...............................................................................................................................................................
Finished in 11.6 seconds (files took 5.29 seconds to load)
159 examples, 0 failures
Test output is now clean!
Reference
teamcapybara/capybara: Acceptance test framework for web applications