I will summarize what I learned and stumbled every day. If you find any mistakes in the description, please let us know! I'm always helped by other people's articles, so I hope it helps.
An error that bundler 2.1.4 is specified in Gemfile.lock, but that version of bundler is not found.
Traceback (most recent call last):
2: from
1: from
#abridgement
Could not find 'bundler' (2.1.4) required by your /Users/<username>/<Root directory name>/Gemfile.lock. (Gem::GemNotFoundException)
To update to the latest version installed on your system, run `bundle update --bundler`.
To install the missing version, run `gem install bundler:2.1.4`
It happens when you change the version of Ruby. In rbenv, it is necessary to install gem for each version of Ruby.
gem install bundler -v 2.1.4
Enter and add bundler 2.1.4 to solve it!
https://qiita.com/kodai_0122/items/c4c13e89dd5c4cba1f32 https://qiita.com/YumaInaura/items/64e5721549e4927ce85f https://k-koh.hatenablog.com/entry/2020/01/27/200511