不知道该怎么做才能具体解决这个问题，谷歌搜索并没有解决我的问题。当我尝试：
bundle exec jekyll serve
我被告知：
Could not find eventmachine-1.2.7 in any of the sources
Run `bundle install` to install missing gems.
然后我：
bundle install
只是为了得到这个：
Installing eventmachine 1.2.7 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
current directory: /private/var/folders/7f/2c2swwc1153899dmr8781_x40000gn/T/bundler20201130-34411-1lzt2fceventmachine-1.2.7/gems/eventmachine-1.2.7/ext
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby -I /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0 -r
./siteconf20201130-34411-pd54nh.rb extconf.rb
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/include/ruby.h
You might have to install separate package for the ruby development
environment, ruby-dev or ruby-devel for example.
extconf failed, exit code 1 …