puma-dev do not work with error message rbenv: puma: command not found

Question

When try to open site get error message unexpected exit:

Check dev logs tail -f log/development.log:

rbenv: puma: command not found

The `puma' command exists in these Ruby versions:
2.4.0

While search for answer found that the most common problem was that there is no line gem 'puma' in Gemfile. But in my case already have this line.

Answer 1

Solution that helped: gem install puma