meaning less rspec uninitialized constant error : I have a rails app and running on a VPS, the installation steps of Ruby, Rails, and RSpec are identical on my laptop and VPS (followed by the [same instruction][1]).<br />But when I want to test the app using RSpec on the VPS it gives the `uninitialized constant` error (something like [this][2]). the exact clone of the project runs perfectly without any errors on my laptop!<br />
Although the tests are executing on my laptop without any problems, I tried the solutions exist on the web but didn't help me -- even I reinstalled Ruby, Rails, and RSpec on the server!

###Quesions:
1. What is wrong with RSpec?
2. How can I fix this?


  [1]: https://gorails.com/setup/ubuntu/18.04
  [2]: https://stackoverflow.com/questions/19692297/rspec-testing-throws-uninitialized-constant-rails-nameerror