Traceback (most recent call last):
	2: from /Users/chenyang/.rvm/gems/ruby-2.7.1/bin/bundle:23:in `<main>'
	1: from /Users/chenyang/.rvm/rubies/ruby-2.7.1/lib/ruby/2.7.0/rubygems.rb:294:in `activate_bin_path'
/Users/chenyang/.rvm/rubies/ruby-2.7.1/lib/ruby/2.7.0/rubygems.rb:275:in `find_spec_for_exe': Could not find 'bundler' (1.16.0) required by your /Users/chenyang/source/xxd3vin.github.io/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:1.16.0`

Solution

$ bundle update --bundler

References