깃헙 블로그 만들기 참고 자료

bundler 버전 설치된거 다 보여주는거 gem list | grep bundler
gem uninstall bundler
gem install bundler --version '1.0.0'
https://stackoverflow.com/questions/57306611/how-can-i-remove-default-version-of-bundler

/Library/Ruby/Gems/2.3.0/gems/bundler-2.2.6
$ rm ~/.rvm/rubies/ruby-2.7.0/lib/ruby/gems/2.7.0/specifications/default/bundler-2.1.2.gemspec

rm -r directory1
// directory1 폴더 및 안의 파일 다 지우기.
rm -rf directory1
// 묻지도 따지지도 않고 다 지우기. (-f 옵션 + -r 옵션)

https://gamsungcoding.tistory.com/entry/Ruby-rbenv%EB%A1%9C-ruby-%EB%B2%84%EC%A0%84-%EB%B3%80%EA%B2%BD%EC%9D%B4-%EC%95%88%EB%90%A0-%EB%95%8C

For those who use rbenv, let say by accidentally you have two default versions
https://stackoverflow.com/questions/57306611/how-can-i-remove-default-version-of-bundler

$ gem environment -> 버전별 bundlers gemspec 위치 확인가능

https://astrocoke.tistory.com/40

https://github.com/jekyll/jekyll/issues/8523