更新码云博客后，想在本地测试一下。上次更新仓库是2年前了，这次爆出一堆问题，参考网上一篇文章解决了。
报错
% jekyll serve
zsh: /usr/local/bin/jekyll: bad interpreter: /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby: no such file or directory
查看ruby版本
% ruby --version
ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin19]
一、更新jekyll
sudo gem install bundler jekyll
又装了一大堆东西。
新的报错
% jekyll serve
Traceback (most recent call last):
12: from /usr/local/bin/jekyll:23:in `<main>'
11: from /usr/local/bin/jekyll:23:in `load'
10: from /Library/Ruby/Gems/2.6.0/gems/jekyll-4.0.0/exe/jekyll:11:in `<top (required)>'
9: from /Library/Ruby/Gems/2.6.0/gems/jekyll-4.0.0/lib/jekyll/plugin_manager.rb:52:in `require_from_bundler'
8: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler.rb:107:in `setup'
7: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:20:in `setup'
6: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:108:in `block in definition_method'
5: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/definition.rb:226:in `requested_specs'
4: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/definition.rb:237:in `specs_for'
3: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/definition.rb:170:in `specs'
2: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/spec_set.rb:85:in `materialize'
1: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/spec_set.rb:85:in `map!'
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/spec_set.rb:91:in `block in materialize': Could not find public_suffix-3.0.2 in any of the sources (Bundler::GemNotFound)
更新bundle。很慢，还以为卡死了。中间要输密码。
太慢了，因为Gemfile.lock写死了gem的源：
GEM
remote: https://rubygems.org/
改镜像
$ bundle config mirror.https://rubygems.org https://gems.ruby-china.com
改完镜像，瞬间升级完成
% bundle update
还是报错
% jekyll serve
Traceback (most recent call last):
10: from /usr/local/bin/jekyll:23:in `<main>'
9: from /usr/local/bin/jekyll:23:in `load'
8: from /Library/Ruby/Gems/2.6.0/gems/jekyll-4.0.0/exe/jekyll:11:in `<top (required)>'
7: from /Library/Ruby/Gems/2.6.0/gems/jekyll-4.0.0/lib/jekyll/plugin_manager.rb:52:in `require_from_bundler'
6: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler.rb:107:in `setup'
5: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:26:in `setup'
4: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:26:in `map'
3: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/forwardable.rb:230:in `each'
2: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/forwardable.rb:230:in `each'
1: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:31:in `block in setup'
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/bundler/runtime.rb:319:in `check_for_activated_spec!': You have already activated i18n 1.8.2, but your Gemfile requires i18n 0.9.5. Prepending `bundle exec` to your command may solve this. (Gem::LoadError)
解：
加上bundle exec，运行成功
% bundle exec jekyll serve
Configuration file: /Users/luojinrong/code/GitHub/obarong.github.io/_config.yml
Source: /Users/luojinrong/code/GitHub/obarong.github.io
Destination: /Users/luojinrong/code/GitHub/obarong.github.io/_site
Incremental build: disabled. Enable with --incremental
Generating...
Jekyll Feed: Generating feed for posts
done in 0.708 seconds.
Auto-regeneration: enabled for '/Users/luojinrong/code/GitHub/obarong.github.io'
Server address: http://127.0.0.1:4000/
Server running... press ctrl-c to stop.
二、升级本地仓库用的Jekyll版本（这节可以跳过）
在仓库目录查看Jekyll版本会出现之前那个报错，要去没有Gemfile的目录。
% jekyll -v
jekyll 4.0.0
在仓库目录实际用的是3.8.6
% bundle exec jekyll -v
jekyll 3.8.6
修改Gemfile
gem "jekyll", "~> 4.0.0"
更新
% bundle install
The dependency tzinfo-data (>= 0) will be unused by any of the platforms Bundler is installing for. Bundler is installing for ruby but the dependency is only for x86-mingw32, x86-mswin32, x64-mingw32, java. To add those platforms to the bundle, run `bundle lock --add-platform x86-mingw32 x86-mswin32 x64-mingw32 java`.
Fetching gem metadata from https://rubygems.org/............
Fetching gem metadata from https://rubygems.org/..
You have requested:
jekyll ~> 4.0.0
The bundle currently has jekyll locked at 3.8.6.
Try running `bundle update jekyll`
If you are updating multiple gems in your Gemfile at once,
try passing them all to `bundle update`
% bundle update jekyll
成功升级仓库的Jekyll。这下可以直接执行jekyll serve了。
三、本地改用GitHub pages主题
为什么GitHub pages的显示效果比我本地的好？
修改Gemfile
#gem "jekyll", "~> 4.0.0"
……
gem "github-pages", group: :jekyll_plugins
报错
% bundle update github-pages
Could not find gem 'github-pages'.
解：
% sudo gem install github-pages
install和update走起
% bundle update
这下本地浏览效果跟GitHub一模一样，但是要加bundle exec启动。
参考
解决因macOS High Sierra更新Ruby到2.3造成的Jekyll不能启动的问题 | 大专栏
https://www.dazhuanlan.com/2019/08/21/5d5c525c9e454/
bundle install 无响应问题 | 大专栏
https://www.dazhuanlan.com/2020/01/07/5e142e02df589/
个人博客搭建之一步步使用Github Page创建博客主页（2） | 大专栏
https://www.dazhuanlan.com/2020/02/02/5e366f389c663/