$ bundle install Traceback (most recent call last): 2: from /Users/<user名>/.rbenv/versions/2.5.3/bin/bundle:23:in `<main>' 1: from /Users/<user名>/.rbenv/versions/2.5.3/lib/ruby/2.5.0/rubygems.rb:308:in `activate_bin_path' /Users/<user名>/.rbenv/versions/2.5.3/lib/ruby/2.5.0/rubygems.rb:289:in `find_spec_for_exe': can't find gem bundler (>= 0.a) with executable bundle (Gem::GemNotFoundException)