Jekyll build -- cannot find _layout, _include, _sass dir for minima theme

I am using Mac 10.11.6 El Capitan. I successfully installed jekyll and used homebrew to install Ruby 2.4.1 to /usr/local/bin. And when I run ruby in terminal, it is the new >2.0.0 ruby I’ve installed. I have GEM_PATH set to "/Users/peter.chen/.rvm/gems/ruby-2.4.1:/Users/peter.chen/.rvm/gems/ruby-2.4.1@global ". But when I do “jekyll new [PATH]”, the _layout, _include _sass folder are not created but the config file has the theme minima. But when I do Jekyll build I get the following errors which result in an index.html that is empty:

 Build Warning: Layout 'post' requested in personal/_posts/2017-12-31-welcome-to-jekyll.markdown does not exist.
 Build Warning: Layout 'default' requested in personal/404.html does not exist.                               
 Build Warning: Layout 'page' requested in personal/about.md does not exist.                                  
 Build Warning: Layout 'home' requested in personal/index.md does not exist.

It seems that jekyll isn’t able to see that I am using the minima theme and then go find it in " /Users/peter.chen/.rvm/gems/ruby-2.4.1/gems/minima-2.1.1"

the theme is hidden, so not seeing it in the folder is normal.

How are you running jekyll? just jekyll serve/build or are you using bundler? I think you need to use bundle exec jekyll serve and that will install the minima theme gem for you.

I don’t use bundler so not sure I have it correct - but I would guess that is your problem, the minima theme gem is missing.

I see, you are right, I was following this tutorial, it made it sound jekyll new creates a folder for all your stuff and you run jekyll outside of that. It works now that I run inside the folder jekyll generated.