title: Only one version of Ruby works when multiple versions are installed
body: <p><strong>Edit 1:</strong> Another person reported <a href="https://github.com/asdf-vm/asdf-ruby/issues/154" rel="nofollow noreferrer">similar issue</a> with asdf.</p>
  
  <p><strong>Edit 2:</strong> Another reported <a href="https://github.com/rvm/rvm/issues/4859" rel="nofollow noreferrer">similar issue</a>.</p>
  
  <p><strong>Edit 3:</strong> I uninstalled <code>rvm</code>, installed <code>rvm</code>, installed <code>ruby</code> and <code>rails</code>, and attempted some activities.</p>
  
  <p><strong>Edit 4:</strong> <a href="https://github.com/rvm/rvm/issues/4859#issuecomment-577618479" rel="nofollow noreferrer">Another person mentioned</a> that it's caused by the line I put into <code>.zshrc</code> (or <code>.bash_profile/.bashrc</code>):
  <code>RUBYOPT: "-W:no-deprecated -W:no-experimental"</code>. </p>
  
  <p>Problem: I have two projects, one using <code>ruby-2.7.0</code>, the other using <code>ruby-2.6.5</code>. </p>
  
  <p>Every time I installed over two versions of ruby, only one version ends up working (2.7.0). The <code>bundle</code> as well as <code>gem</code> commands on the other will no longer work but give a <code>Traceback....(RuntimeError)</code>.</p>
  
  <p><strong>Most Recent Attempt and Console Outputs:</strong>
  Console output flow is roughly: </p>
  
  <ol>
  <li>Uninstall <code>rvm</code></li>
  <li>Install <code>rvm</code></li>
  <li>Install <code>ruby-2.7.0</code></li>
  <li>Install <code>ruby-2.6.5</code></li>
  <li>For <code>ruby-2.7.0</code>, install <code>rails</code></li>
  <li>For <code>ruby-2.6.5</code>, install <code>rails</code></li>
  <li>Everything working alright so far</li>
  <li>Append <code>export PATH="$PATH:$HOME/.rvm/bin"</code> to ~/.zshrc</li>
  <li>Still working alright</li>
  <li>Did <code>echo "export RUBYOPT='-W:no-deprecated -W:no-experimental'" &gt;&gt; ~/.zshrc</code>; <code>source ~/.zshrc</code></li>
  <li>Started noticing the problem again</li>
  <li><code>ruby-2.6.5</code> does not work; <code>ruby-2.7.0</code> still works</li>
  </ol>
  
  <pre><code># UNINSTALL RVM
  (base) ➜  ~ rvm -v
  rvm 1.29.9 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
  (base) ➜  ~ which ruby
  /Users/nahua/.rvm/rubies/ruby-2.6.5/bin/ruby
  (base) ➜  ~ which rails
  /usr/bin/rails
  (base) ➜  ~ rbenv
  zsh: command not found: rbenv
  (base) ➜  ~
  
  (base) ➜  ~ rvm implode
  Are you SURE you wish for rvm to implode?
  This will recursively remove /Users/nahua/.rvm and other rvm traces?
  (anything other than 'yes' will cancel) &gt; yes
  Removing rvm-shipped binaries (rvm-prompt, rvm, rvm-sudo rvm-shell and rvm-auto-ruby)
  Removing rvm wrappers in /Users/nahua/.rvm/bin
  Hai! Removing /Users/nahua/.rvm
  /Users/nahua/.rvm has been removed.
  
  Note you may need to manually remove /etc/rvmrc and ~/.rvmrc if they exist still.
  Please check all .bashrc .bash_profile .profile and .zshrc for RVM source lines and delete or comment out if this was a Per-User installation.
  Also make sure to remove `rvm` group if this was a system installation.
  Finally it might help to relogin / restart if you want to have fresh environment (like for installing RVM again).
  
  (base) ➜  ~ gem uninstall rvm
  Traceback (most recent call last):
  /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  ~ which ruby
  /usr/bin/ruby
  (base) ➜  ~ rvm -v
  cat: /Users/nahua/.rvm/VERSION: No such file or directory
  __rvm_initialize:source:4: no such file or directory: /Users/nahua/.rvm/scripts/base
  cat: /Users/nahua/.rvm/VERSION: No such file or directory
  rvm  () by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
  
  # COMMENT OFF ALL RVM LINES IN THE FOLLOWING FILES
  (base) ➜  ~ subl .bashrc
  (base) ➜  ~ subl .profile
  (base) ➜  ~ subl .zshrc
  (base) ➜  ~ subl .bash_profile
  (base) ➜  ~ subl .zlogin
  (base) ➜  ~ subl /etc/profile # nothing there
  (base) ➜  ~ sudo vim /etc/profile # nothing there
  Password:
  (base) ➜  ~ exit
  
  # RESTART TERMINAL
  (base) ➜  ~ ruby -v
  ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin19]
  (base) ➜  ~ which ruby
  /usr/bin/ruby
  (base) ➜  ~ which gem
  /usr/bin/gem
  (base) ➜  ~ which bundle
  /usr/bin/bundle
  (base) ➜  ~ clear
  (base) ➜  ~ rvm list
  zsh: command not found: rvm
  (base) ➜  ~ rbenv versions
  zsh: command not found: rbenv
  
  # INSTALL RVM
  (base) ➜  ~ gpg --keyserver hkp://pool.sks-keyservers.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
  Warning: Failed to set locale category LC_NUMERIC to en_DE.
  Warning: Failed to set locale category LC_TIME to en_DE.
  Warning: Failed to set locale category LC_COLLATE to en_DE.
  Warning: Failed to set locale category LC_MONETARY to en_DE.
  Warning: Failed to set locale category LC_MESSAGES to en_DE.
  gpg: key 105BD0E739499BDB: "Piotr Kuczynski &lt;piotr.kuczynski@gmail.com&gt;" not changed
  gpg: key 3804BB82D39DC0E3: "Michal Papis (RVM signing) &lt;mpapis@gmail.com&gt;" not changed
  gpg: Total number processed: 2
  gpg:              unchanged: 2
  (base) ➜  ~ \curl -sSL https://get.rvm.io | bash -s stable --ruby
  Downloading https://github.com/rvm/rvm/archive/1.29.9.tar.gz
  Downloading https://github.com/rvm/rvm/releases/download/1.29.9/1.29.9.tar.gz.asc
  Warning: Failed to set locale category LC_NUMERIC to en_DE.
  Warning: Failed to set locale category LC_TIME to en_DE.
  Warning: Failed to set locale category LC_COLLATE to en_DE.
  Warning: Failed to set locale category LC_MONETARY to en_DE.
  Warning: Failed to set locale category LC_MESSAGES to en_DE.
  gpg: Signature made Wed Jul 10 10:31:02 2019 CEST
  gpg:                using RSA key 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
  gpg: Good signature from "Piotr Kuczynski &lt;piotr.kuczynski@gmail.com&gt;" [unknown]
  gpg: WARNING: This key is not certified with a trusted signature!
  gpg:          There is no indication that the signature belongs to the owner.
  Primary key fingerprint: 7D2B AF1C F37B 13E2 069D  6956 105B D0E7 3949 9BDB
  GPG verified '/Users/nahua/.rvm/archives/rvm-1.29.9.tgz'
  Installing RVM to /Users/nahua/.rvm/
      RVM PATH line found in /Users/nahua/.mkshrc /Users/nahua/.profile /Users/nahua/.bashrc /Users/nahua/.zshrc.
      RVM sourcing line found in /Users/nahua/.profile /Users/nahua/.bash_profile /Users/nahua/.zlogin.
  Installation of RVM in /Users/nahua/.rvm/ is almost complete:
  
    * To start using RVM you need to run `source /Users/nahua/.rvm/scripts/rvm`
      in all your open shell windows, in rare cases you need to reopen all shell windows.
  Thanks for installing RVM 
  Please consider donating to our open collective to help us maintain RVM.
  
    Donate: https://opencollective.com/rvm/donate
  
  
  Ruby enVironment Manager 1.29.9 (latest) (c) 2009-2017 Michal Papis, Piotr Kuczynski, Wayne E. Seguin
  
  Searching for binary rubies, this might take some time.
  No binary rubies available for: osx/10.15/x86_64/ruby-2.6.3.
  Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
  Checking requirements for osx.
  Certificates bundle '/usr/local/etc/openssl@1.1/cert.pem' is already up to date.
  Requirements installation successful.
  Installing Ruby from source to: /Users/nahua/.rvm/rubies/ruby-2.6.3, this may take a while depending on your cpu(s)...
  ruby-2.6.3 - #downloading ruby-2.6.3, this may take a while depending on your connection...
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100 13.8M  100 13.8M    0     0  4529k      0  0:00:03  0:00:03 --:--:-- 4529k
  ruby-2.6.3 - #extracting ruby-2.6.3 to /Users/nahua/.rvm/src/ruby-2.6.3.....
  ruby-2.6.3 - #configuring.......................................................................
  ruby-2.6.3 - #post-configuration.
  ruby-2.6.3 - #compiling.....................................................................
  ruby-2.6.3 - #installing...........
  ruby-2.6.3 - #making binaries executable..
  ruby-2.6.3 - #downloading rubygems-3.0.6
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100  866k  100  866k    0     0  3437k      0 --:--:-- --:--:-- --:--:-- 3437k
  No checksum for downloaded archive, recording checksum in user configuration.
  ruby-2.6.3 - #extracting rubygems-3.0.6.....
  ruby-2.6.3 - #removing old rubygems........
  $LANG was empty, setting up LANG=en_US.US-ASCII, if it fails again try setting LANG to something sane and try again.
  ruby-2.6.3 - #installing rubygems-3.0.6...............................................
  ruby-2.6.3 - #gemset created /Users/nahua/.rvm/gems/ruby-2.6.3@global
  ruby-2.6.3 - #importing gemset /Users/nahua/.rvm/gemsets/global.gems......................................................-
  ruby-2.6.3 - #generating global wrappers.......
  ruby-2.6.3 - #gemset created /Users/nahua/.rvm/gems/ruby-2.6.3
  ruby-2.6.3 - #importing gemsetfile /Users/nahua/.rvm/gemsets/default.gems evaluated to empty gem list
  ruby-2.6.3 - #generating default wrappers.......
  ruby-2.6.3 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
  Install of ruby-2.6.3 - #complete
  Ruby was built without documentation, to build it run: rvm docs generate-ri
  Creating alias default for ruby-2.6.3....
  
    * To start using RVM you need to run `source /Users/nahua/.rvm/scripts/rvm`
      in all your open shell windows, in rare cases you need to reopen all shell windows.
  (base) ➜  ~ source /Users/nahua/.rvm/scripts/rvm
  source /Users/nahua/.rvm/scripts/rvm
  (base) ➜  ~ rvm
  Ruby enVironment Manager 1.29.9 (latest) (c) 2009-2017 Michal Papis, Piotr Kuczynski, Wayne E. Seguin
  
  
  For additional documentation please visit https://rvm.io
  
  (base) ➜  ~ echo $PATH
  /Users/nahua/.rvm/gems/ruby-2.6.3/bin:/Users/nahua/.rvm/gems/ruby-2.6.3@global/bin:/Users/nahua/.rvm/rubies/ruby-2.6.3/bin:/opt/anaconda3/bin:/opt/anaconda3/condabin:/Users/nahua/bin:/usr/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/nahua/.rvm/bin
  (base) ➜  ~ rvm -v
  rvm 1.29.9 (latest) by Michal Papis, Piotr Kuczynski, Wayne E. Seguin [https://rvm.io]
  (base) ➜  ~ rvm list
  =* ruby-2.6.3 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  ~ rvm install 2.7.0
  Searching for binary rubies, this might take some time.
  No binary rubies available for: osx/10.15/x86_64/ruby-2.7.0.
  Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
  Checking requirements for osx.
  Certificates bundle '/usr/local/etc/openssl@1.1/cert.pem' is already up to date.
  Requirements installation successful.
  Installing Ruby from source to: /Users/nahua/.rvm/rubies/ruby-2.7.0, this may take a while depending on your cpu(s)...
  ruby-2.7.0 - #downloading ruby-2.7.0, this may take a while depending on your connection...
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100 14.0M  100 14.0M    0     0  4616k      0  0:00:03  0:00:03 --:--:-- 4616k
  No checksum for downloaded archive, recording checksum in user configuration.
  ruby-2.7.0 - #extracting ruby-2.7.0 to /Users/nahua/.rvm/src/ruby-2.7.0 - please wait
  ruby-2.7.0 - #configuring - please wait
  ruby-2.7.0 - #post-configuration - please wait
  ruby-2.7.0 - #compiling - please wait
  ruby-2.7.0 - #installing - please wait
  ruby-2.7.0 - #making binaries executable - please wait
  Installed rubygems 3.1.2 is newer than 3.0.6 provided with installed ruby, skipping installation, use --force to force installation.
  ruby-2.7.0 - #gemset created /Users/nahua/.rvm/gems/ruby-2.7.0@global
  ruby-2.7.0 - #importing gemset /Users/nahua/.rvm/gemsets/global.gems - please wait
  ruby-2.7.0 - #generating global wrappers - please wait
  ruby-2.7.0 - #gemset created /Users/nahua/.rvm/gems/ruby-2.7.0
  ruby-2.7.0 - #importing gemsetfile /Users/nahua/.rvm/gemsets/default.gems evaluated to empty gem list
  ruby-2.7.0 - #generating default wrappers - please wait
  ruby-2.7.0 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
  Install of ruby-2.7.0 - #complete
  Ruby was built without documentation, to build it run: rvm docs generate-ri
  (base) ➜  ~ rvm list
   * ruby-2.6.3 [ x86_64 ]
  =&gt; ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  ~ gem -v
  3.1.2
  (base) ➜  ~ bundle -v
  Bundler version 2.1.2
  (base) ➜  ~ rvm use 2.6.3
  Using /Users/nahua/.rvm/gems/ruby-2.6.3
  (base) ➜  ~ ruby -v
  ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-darwin19]
  (base) ➜  ~ gem -v
  3.0.6
  (base) ➜  ~ bundle -v
  Bundler version 1.17.3
  (base) ➜  ~ rvm use 2.7.0
  Using /Users/nahua/.rvm/gems/ruby-2.7.0
  (base) ➜  ~ ruby -v
  ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]
  (base) ➜  ~ gem -v
  3.1.2
  (base) ➜  ~ bundle -v
  Bundler version 2.1.2
  (base) ➜  ~ rvm install 2.6.5
  Searching for binary rubies, this might take some time.
  No binary rubies available for: osx/10.15/x86_64/ruby-2.6.5.
  Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies.
  Checking requirements for osx.
  Certificates bundle '/usr/local/etc/openssl@1.1/cert.pem' is already up to date.
  Requirements installation successful.
  Installing Ruby from source to: /Users/nahua/.rvm/rubies/ruby-2.6.5, this may take a while depending on your cpu(s)...
  ruby-2.6.5 - #downloading ruby-2.6.5, this may take a while depending on your connection...
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100 13.4M  100 13.4M    0     0  9377k      0  0:00:01  0:00:01 --:--:-- 9370k
  No checksum for downloaded archive, recording checksum in user configuration.
  ruby-2.6.5 - #extracting ruby-2.6.5 to /Users/nahua/.rvm/src/ruby-2.6.5 - please wait
  ruby-2.6.5 - #configuring - please wait
  ruby-2.6.5 - #post-configuration - please wait
  ruby-2.6.5 - #compiling - please wait
  ruby-2.6.5 - #installing - please wait
  ruby-2.6.5 - #making binaries executable - please wait
  ruby-2.6.5 - #downloading rubygems-3.0.6
  ruby-2.6.5 - #extracting rubygems-3.0.6 - please wait
  ruby-2.6.5 - #removing old rubygems - please wait
  $LANG was empty, setting up LANG=en_US.US-ASCII, if it fails again try setting LANG to something sane and try again.
  ruby-2.6.5 - #installing rubygems-3.0.6 - please wait
  ruby-2.6.5 - #gemset created /Users/nahua/.rvm/gems/ruby-2.6.5@global
  ruby-2.6.5 - #importing gemset /Users/nahua/.rvm/gemsets/global.gems - please wait
  ruby-2.6.5 - #generating global wrappers - please wait
  ruby-2.6.5 - #gemset created /Users/nahua/.rvm/gems/ruby-2.6.5
  ruby-2.6.5 - #importing gemsetfile /Users/nahua/.rvm/gemsets/default.gems evaluated to empty gem list
  ruby-2.6.5 - #generating default wrappers - please wait
  ruby-2.6.5 - #adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
  Install of ruby-2.6.5 - #complete
  Ruby was built without documentation, to build it run: rvm docs generate-ri
  (base) ➜  ~ ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  ~ gem -v
  3.0.6
  (base) ➜  ~ bundle -v
  Bundler version 1.17.3
  (base) ➜  ~ gem install rails
  ...
  IGNORED DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Successfully installed concurrent-ruby-1.1.5
  
  HEADS UP! i18n 1.1 changed fallbacks to exclude default locale.
  But that may break your application.
  
  If you are upgrading your Rails application from an older version of Rails:
  
  Please check your Rails app for 'config.i18n.fallbacks = true'.
  If you're using I18n (&gt;= 1.1.0) and Rails (&lt; 5.2.2), this should be
  'config.i18n.fallbacks = [I18n.default_locale]'.
  If not, fallbacks will be broken in your app by I18n 1.1.x.
  
  If you are starting a NEW Rails application, you can ignore this notice.
  
  For more info see:
  https://github.com/svenfuchs/i18n/releases/tag/v1.1.0
  ...
  IGNORED DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Done installing documentation for concurrent-ruby, i18n, thread_safe, tzinfo, zeitwerk, activesupport, rack, rack-test, mini_portile2, nokogiri, crass, loofah, rails-html-sanitizer, rails-dom-testing, builder, erubi, actionview, actionpack, activemodel, activerecord, globalid, activejob, mini_mime, mail, actionmailer, nio4r, websocket-extensions, websocket-driver, actioncable, mimemagic, marcel, activestorage, actionmailbox, actiontext, thor, method_source, railties, sprockets, sprockets-rails, rails after 39 seconds
  40 gems installed
  (base) ➜  ~ rails -v
  Rails 6.0.2.1
  (base) ➜  ~ rvm use 2.6.5
  Using /Users/nahua/.rvm/gems/ruby-2.6.5
  (base) ➜  ~ ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  ~ gem install rails
  ...
  IGNORED DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Successfully installed concurrent-ruby-1.1.5
  
  HEADS UP! i18n 1.1 changed fallbacks to exclude default locale.
  But that may break your application.
  
  If you are upgrading your Rails application from an older version of Rails:
  
  Please check your Rails app for 'config.i18n.fallbacks = true'.
  If you're using I18n (&gt;= 1.1.0) and Rails (&lt; 5.2.2), this should be
  'config.i18n.fallbacks = [I18n.default_locale]'.
  If not, fallbacks will be broken in your app by I18n 1.1.x.
  
  If you are starting a NEW Rails application, you can ignore this notice.
  
  For more info see:
  https://github.com/svenfuchs/i18n/releases/tag/v1.1.0
  
  ...
  IGNORED DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Done installing documentation for concurrent-ruby, i18n, thread_safe, tzinfo, zeitwerk, activesupport, rack, rack-test, mini_portile2, nokogiri, crass, loofah, rails-html-sanitizer, rails-dom-testing, builder, erubi, actionview, actionpack, activemodel, activerecord, globalid, activejob, mini_mime, mail, actionmailer, nio4r, websocket-extensions, websocket-driver, actioncable, mimemagic, marcel, activestorage, actionmailbox, actiontext, thor, method_source, railties, sprockets, sprockets-rails, rails after 34 seconds
  40 gems installed
  (base) ➜  ~ ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  ~ rvm list
   * ruby-2.6.3 [ x86_64 ]
  =&gt; ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  ~ rvm use 2.7.0
  Using /Users/nahua/.rvm/gems/ruby-2.7.0
  (base) ➜  ~ ruby -v
  ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]
  (base) ➜  ~ rvm use 2.6.5
  Using /Users/nahua/.rvm/gems/ruby-2.6.5
  (base) ➜  ~ ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  ~ cd projects/rails/DevcampPortfolio
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ cat .ruby-version
  2.7.0
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rvm list
   * ruby-2.6.3 [ x86_64 ]
     ruby-2.6.5 [ x86_64 ]
  =&gt; ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rails c
  Warning: the running version of Bundler (2.1.2) is older than the version that created the lockfile (2.1.4). We suggest you to upgrade to the version that created the lockfile by running `gem install bundler:2.1.4`.
  Could not find minitest-5.14.0 in any of the sources
  Run `bundle install` to install missing gems.
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ clear
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ which bundle
  /Users/nahua/.rvm/rubies/ruby-2.7.0/bin/bundle
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ bundle install
  Warning: the running version of Bundler (2.1.2) is older than the version that created the lockfile (2.1.4). We suggest you to upgrade to the version that created the lockfile by running `gem install bundler:2.1.4`.
  Fetching gem metadata from https://rubygems.org/............
  ...
  ### BUNDLE INSTALL...DELETING DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Bundle complete! 15 Gemfile dependencies, 67 gems now installed.
  Use `bundle info [gemname]` to see where a bundled gem is installed.
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ gem install bundler:2.1.4
  Fetching bundler-2.1.4.gem
  Successfully installed bundler-2.1.4
  Parsing documentation for bundler-2.1.4
  Installing ri documentation for bundler-2.1.4
  Done installing documentation for bundler after 2 seconds
  1 gem installed
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rvm use 2.6.5
  Using /Users/nahua/.rvm/gems/ruby-2.6.5
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rvm use 2.7.0
  Using /Users/nahua/.rvm/gems/ruby-2.7.0
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ ruby -v
  ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rails c
  Warning: the running version of Bundler (2.1.2) is older than the version that created the lockfile (2.1.4). We suggest you to upgrade to the version that created the lockfile by running `gem install bundler:2.1.4`.
  Running via Spring preloader in process 16581
  Loading development environment (Rails 6.0.2.1)
  2.7.0 :001 &gt; exit
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ cd ../../20bn-homepage
  (base) ➜  20bn-homepage git:(master) rvm list
   * ruby-2.6.3 [ x86_64 ]
  =&gt; ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  20bn-homepage git:(master) bundle install
  You must use Bundler 2 or greater with this lockfile.
  (base) ➜  20bn-homepage git:(master) bundle -v
  Bundler version 1.17.3
  (base) ➜  20bn-homepage git:(master) gem install bundler:2.1.4
  Fetching bundler-2.1.4.gem
  Successfully installed bundler-2.1.4
  Parsing documentation for bundler-2.1.4
  Installing ri documentation for bundler-2.1.4
  Done installing documentation for bundler after 2 seconds
  1 gem installed
  
  (base) ➜  20bn-homepage git:(master) bundle install
  You must use Bundler 2 or greater with this lockfile.
  (base) ➜  20bn-homepage git:(master) bundle -v
  Bundler version 1.17.3
  (base) ➜  20bn-homepage git:(master) gem install bundler:2.1.4
  Fetching bundler-2.1.4.gem
  Successfully installed bundler-2.1.4
  Parsing documentation for bundler-2.1.4
  Installing ri documentation for bundler-2.1.4
  Done installing documentation for bundler after 2 seconds
  1 gem installed
  (base) ➜  20bn-homepage git:(master) bundle install
  ...
  ### BUNDLE INSTALL...DELETING DUE TO CHARACTER LIMIT ON STACKOVERFLOW
  ...
  Bundle complete! 61 Gemfile dependencies, 180 gems now installed.
  Use `bundle info [gemname]` to see where a bundled gem is installed.
  Post-install message from postmark:
  
      ==================
      Thanks for installing the postmark gem. If you don't have an account, please
      sign up at http://postmarkapp.com/.
  
      Review the README.md for implementation details and examples.
      ==================
    %
  
  (base) ➜  20bn-homepage git:(master) exit
  Last login: Wed Jan 22 10:05:43 on ttys001
  (base) ➜  ~ rvm list
  zsh: command not found: rvm
  (base) ➜  ~ echo "source $HOME/.rvm/scripts/rvm" &gt;&gt; ~/.zshrc
  (base) ➜  ~ source ~/.zshrc
  (base) ➜  ~ rvm list
  =* ruby-2.6.3 [ x86_64 ]
     ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  ~ ruby -v
  ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-darwin19]
  (base) ➜  ~ cd projects/rails/DevcampPortfolio
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rvm list
   * ruby-2.6.3 [ x86_64 ]
     ruby-2.6.5 [ x86_64 ]
  =&gt; ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rails c
  Warning: the running version of Bundler (2.1.2) is older than the version that created the lockfile (2.1.4). We suggest you to upgrade to the version that created the lockfile by running `gem install bundler:2.1.4`.
  Running via Spring preloader in process 26256
  Loading development environment (Rails 6.0.2.1)
   :001 &gt; Blog.last
    Blog Load (2.5ms)  SELECT "blogs".* FROM "blogs" ORDER BY "blogs"."id" DESC LIMIT $1  [["LIMIT", 1]]
   =&gt; #&lt;Blog id: 12, title: "My great blog title", body: "Lorem ipsum blah blah blah", created_at: "2020-01-21 09:49:26", updated_at: "2020-01-21 09:49:26", slug: "my-great-blog-title"&gt;
   :002 &gt; exit
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ cd ../../20bn-homepage
  (base) ➜  20bn-homepage git:(master) rvm list
   * ruby-2.6.3 [ x86_64 ]
  =&gt; ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  20bn-homepage git:(master) ruby -v
  ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
  (base) ➜  20bn-homepage git:(master) rails c
  Loading development environment (Rails 6.0.2.1)
   :001 &gt; exit
  (base) ➜  20bn-homepage git:(master) cd ../rails/DevcampPortfolio
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ echo "export RUBYOPT='-W:no-deprecated -W:no-experimental'" &gt;&gt; ~/.zshrc
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ source ~/.zshrc
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ rails c
  Warning: the running version of Bundler (2.1.2) is older than the version that created the lockfile (2.1.4). We suggest you to upgrade to the version that created the lockfile by running `gem install bundler:2.1.4`.
  Running via Spring preloader in process 26693
  Loading development environment (Rails 6.0.2.1)
  2.7.0 :001 &gt; exit
  (base) ➜  DevcampPortfolio git:(portfolio-feature) ✗ cd ../../20bn-homepage
  (base) ➜  20bn-homepage git:(master) ruby -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  
  ### COMMENT OFF export RUBYOPT='-W:no-deprecated -W:no-experimental' IN ~/.zshrc AGAIN
  
  (base) ➜  20bn-homepage git:(master) source ~/.zshrc
  (base) ➜  20bn-homepage git:(master) ruby -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  20bn-homepage git:(master)
  (base) ➜  20bn-homepage git:(master) rvm list
  Warning! PATH is not properly set up, /Users/nahua/.rvm/gems/ruby-2.6.5/bin is not at first place.
           Usually this is caused by shell initialization files. Search for PATH=... entries.
           You can also re-add RVM to your profile by running: rvm get stable --auto-dotfiles
           To fix it temporarily in this shell session run: rvm use ruby-2.6.5
           To ignore this error add rvm_silence_path_mismatch_check_flag=1 to your ~/.rvmrc file.
   * ruby-2.6.3 [ x86_64 ]
  =&gt; ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  20bn-homepage git:(master) rvm get stable --auto-dotfiles
  ...
  IGNORED DUE TO STACKOVERFLOW CHARACTER LIMIT
  ...
  
  RVM reloaded!
  
  (base) ➜  20bn-homepage git:(master) ruby -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  
  
  (base) ➜  20bn-homepage git:(master) echo $PATH
  /Users/nahua/bin:/usr/local/bin:/Users/nahua/.rvm/gems/ruby-2.6.5/bin:/Users/nahua/.rvm/gems/ruby-2.6.5@global/bin:/Users/nahua/.rvm/rubies/ruby-2.6.5/bin:/Users/nahua/.rvm/bin:/Users/nahua/bin:/usr/local/bin:/Users/nahua/bin:/usr/local/bin:/opt/anaconda3/bin:/opt/anaconda3/condabin:/Users/nahua/bin:/usr/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
  (base) ➜  20bn-homepage git:(master) rvm reset
  Warning! PATH is not properly set up, /Users/nahua/.rvm/gems/ruby-2.6.5/bin is not at first place.
           Usually this is caused by shell initialization files. Search for PATH=... entries.
           You can also re-add RVM to your profile by running: rvm get stable --auto-dotfiles
           To fix it temporarily in this shell session run: rvm use ruby-2.6.5
           To ignore this error add rvm_silence_path_mismatch_check_flag=1 to your ~/.rvmrc file.
  (base) ➜  20bn-homepage git:(master) ruby -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  20bn-homepage git:(master) rvm list
   * ruby-2.6.3 [ x86_64 ]
     ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  20bn-homepage git:(master) source ~/.zshrc
  (base) ➜  20bn-homepage git:(master) ruby -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  20bn-homepage git:(master) rvm use ruby-2.6.5
  Using /Users/nahua/.rvm/gems/ruby-2.6.5
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  20bn-homepage git:(master) rvm use 2.7.0
  Using /Users/nahua/.rvm/gems/ruby-2.7.0
  (base) ➜  20bn-homepage git:(master) ruby -v
  ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin19]
  </code></pre>
  
  <p><strong>Original Problem Description:</strong></p>
  
  <p>I have two projects, one using <code>ruby-2.7.0</code>, the other using <code>ruby-2.6.5</code>. </p>
  
  <p>I've just realized there is a weird issue with my Ruby/Rails setup on the latest OS X. Either using <code>rvm</code> or <code>rbenv</code>, every time I installed over two versions of ruby, only one version ends up working (2.7.0). The <code>bundle</code> as well as <code>gem</code> commands on the other will no longer work but give a <code>Traceback....(RuntimeError)</code>.</p>
  
  <p>In the past 6 hours, I have reinstalled <code>rbenv</code>, uninstalled <code>rbenv</code>, installed <code>rvm</code>. I've also tried uninstalling all non-system Ruby versions and Rails as well. Nothing seems to help.</p>
  
  <p>Below is the error shown in my console:</p>
  
  <pre><code>(base) ➜  ~ rvm list
  =* ruby-2.6.5 [ x86_64 ]
     ruby-2.7.0 [ x86_64 ]
  
  # =&gt; - current
  # =* - current &amp;&amp; default
  #  * - default
  
  (base) ➜  ~ bundle -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  ~ gem -v
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  (base) ➜  ~ rvm use 2.7.0
  Using /Users/nahua/.rvm/gems/ruby-2.7.0
  (base) ➜  ~ bundle -v
  Bundler version 2.1.4
  (base) ➜  ~ rvm use 2.6.5
  Using /Users/nahua/.rvm/gems/ruby-2.6.5
  Traceback (most recent call last):
  ruby: invalid option -:  (-h will show valid options) (RuntimeError)
  </code></pre>