can't find gem bundler Ruby - ruby-on-rails

Question

Using Mac OS 13, rbenv.
ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17]
Rails 5.1.4
Bundler version 1.16.1
rbenv 1.1.1
I'm trying to start a new Rails application and then getting this:
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems.rb:241:in `bin_path': can't find gem bundler (>= 0) (Gem::GemNotFoundException)
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/generators/app_base.rb:382:in `bundle_command'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/generators/app_base.rb:416:in `run_bundle'
from (eval):1:in `run_bundle'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in `block in invoke_all'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in `each'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in `map'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:133:in `invoke_all'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/group.rb:232:in `dispatch'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/base.rb:466:in `start'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/commands/application/application_command.rb:24:in `perform'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/command/base.rb:63:in `perform'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/command.rb:44:in `invoke'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/lib/rails/cli.rb:16:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `rescue in require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:40:in `require'
from /Library/Ruby/Gems/2.3.0/gems/railties-5.1.4/exe/rails:9:in `<top (required)>'
from /usr/local/bin/rails:22:in `load'
from /usr/local/bin/rails:22:in `<main>'
As I understand it has something to do with a version of Ruby but I have no idea how to resolve the issue.

Answer 1

It looks like you may need to do a gem install bundler and get the bundler gem to get rails up and running.

Answer 2

STEP (1): install the bundler gem:
sudo gem install bundler
Once completed, you should get a message similar to this:
Fetching: bundler-1.16.1.gem (100%)
Successfully installed bundler-1.16.1
Parsing documentation for bundler-1.16.1
Installing ri documentation for bundler-1.16.1
Done installing documentation for bundler after 6 seconds
1 gem installed
STEP (2): try checking the bundler version:
bundle -v
You should get a version number like this:
Bundler version 1.16.1
STEP (3): now you can use bundle install:
bundle install
I hope my answer helps.