Error installing Bundler

Question

I am trying to install the Bundler gem on my Mac. With the command: sudo gem install bundler I get the following error:

ERROR:  Could not find a         


        

Answer 1

for those Chinese users:

$ gem install bundler
ERROR:  Could not find a valid gem 'bundler' (>= 0), here is why:
          Unable to download data from https://rubygems.org/ - Errno::ECONNRESET: Connection reset by peer - SSL_connect (https://api.rubygems.org/latest_specs.4.8.gz)

$ gem sources --add https://ruby.taobao.org/ --remove https://rubygems.org/

$ gem sources  -l
*** CURRENT SOURCES ***

https://ruby.taobao.org/

$ gem install bundler 

Fetching: bundler-1.12.5.gem (100%)
Successfully installed bundler-1.12.5
Parsing documentation for bundler-1.12.5
Installing ri documentation for bundler-1.12.5
Done installing documentation for bundler after 4 seconds
1 gem installed

My environment: rbenv, ruby 2.1.2, ubuntu 16.04 LTS