初试gem

为了安装Jekyll 使用gem  Ruby 社区的 Gem 托管服务

中文镜像站

一、更新

　　sudo gem update

　　gem -v

　　Fetching: nokogiri-1.8.1.gem (100%)　　

　　ERROR:  Error installing nokogiri:

　　nokogiri requires Ruby version >= 2.1.0.

　　安装失败

二、重新安装新版本Ruby

　　1、brew install ruby

Warning: You are using OS X 10.12.
We do not provide support for this pre-release version.
You may encounter build failures or other breakages.
Please create pull-requests instead of filing issues.
==> Installing dependencies for ruby: readline, libyaml
==> Installing ruby dependency: readline
==> Downloading https://ftpmirror.gnu.org/readline/readline-6.3.tar.gz
Already downloaded: /Users/sz/Library/Caches/Homebrew/readline-6.3.8.tar.gz
==> Downloading https://gist.githubusercontent.com/jacknagel/d886531fb6623b60b2af/raw/746fc54

curl: (22) The requested URL returned error: 404 Not Found
Error: Failed to download resource "readline--patch"
Download failed: https://gist.githubusercontent.com/jacknagel/d886531fb6623b60b2af/raw/746fc543e56bc37a26ccf05d2946a45176b0894e/readline-6.3.8.diff

　　依旧失败

　　考虑使用 Ruby-install安装 Ruby安装

　　2、brew install ruby-install 成功！but 安装ruby失败

ruby-install ruby
>>> Updating ruby versions ...
>>> Installing ruby 2.4.2 into /Users/sz/.rubies/ruby-2.4.2 ...
>>> Installing dependencies for ruby 2.4.2 ...
Warning: openssl-1.0.2h_1 already installed
Warning: You are using OS X 10.12.
We do not provide support for this pre-release version.
You may encounter build failures or other breakages.
Please create pull-requests instead of filing issues.
==> Downloading https://ftpmirror.gnu.org/readline/readline-6.3.tar.gz
Already downloaded: /Users/sz/Library/Caches/Homebrew/readline-6.3.8.tar.gz
==> Downloading https://gist.githubusercontent.com/jacknagel/d886531fb6623b60b2af/raw/746fc54

curl: (22) The requested URL returned error: 404 Not Found
Error: Failed to download resource "readline--patch"
Download failed: https://gist.githubusercontent.com/jacknagel/d886531fb6623b60b2af/raw/746fc543e56bc37a26ccf05d2946a45176b0894e/readline-6.3.8.diff
Warning: You are using OS X 10.12.
We do not provide support for this pre-release version.
You may encounter build failures or other breakages.
Please create pull-requests instead of filing issues.
Error: openssl 1.0.2h_1 already installed
Error: readline not installed
Error: libyaml not installed
Error: gdbm not installed
Error: libffi not installed
!!! Installing dependencies failed!

　　3、考虑RVM 安装　

curl -sSL https://get.rvm.io | bash -s stable
Downloading https://github.com/rvm/rvm/archive/1.29.3.tar.gz
Downloading https://github.com/rvm/rvm/releases/download/1.29.3/1.29.3.tar.gz.asc
Found PGP signature at: 'https://github.com/rvm/rvm/releases/download/1.29.3/1.29.3.tar.gz.asc',
but no GPG software exists to validate it, skipping.

Installing RVM to /Users/sz/.rvm/
    Adding rvm PATH line to /Users/sz/.profile /Users/sz/.mkshrc /Users/sz/.bashrc /Users/sz/.zshrc.
    Adding rvm loading line to /Users/sz/.profile /Users/sz/.bash_profile /Users/sz/.zlogin.
Installation of RVM in /Users/sz/.rvm/ is almost complete:

  * To start using RVM you need to run `source /Users/sz/.rvm/scripts/rvm`
    in all your open shell windows, in rare cases you need to reopen all shell windows.
szdeMacBook-Pro:PycharmProjects mxh$ source /Users/sz/.rvm/scripts/rvm

source /Users/sz/.rvm/scripts/rvm

　　新打开terminal   rvm -v 就可以看到版本

rvm 1.29.3 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]

　　rvm 就可以看到帮助   RVM中国

　　修改RVM镜像源后可以在  .rvm/user/db  db文件中查看