Bundler using wrong Ruby version
问题 When I try to start my Rails server, I get the following error: $ bundle exec rails s Your Ruby version is 2.3.7, but your Gemfile specified ~> 2.3.8 I don't understand why that happens though, since I set Ruby to 2.3.8 both using Homebrew and using rbenv. 2.3.7 is the version of the system's ruby. I am using Mac OS 10.14.4. $ ruby -v ruby 2.3.8p459 (2018-10-18 revision 65136) [x86_64-darwin18] $ rbenv version 2.3.8 (set by /Users/ceasar/foo/.ruby-version) $ which -a ruby /Users/ceasar/.rbenv