Weird issue with ruby version on mac - ruby

Question

I am trying to create a rails app and fails like so:
$ rails new blog
Rails 6 requires Ruby 2.5.0 or newer.
You're running:
ruby 2.3.7p456 (2018-03-28 revision 63024) [universal.x86_64-darwin18]
Please upgrade to Ruby 2.5.0 or newer to continue.
However, my ruby version is 2.6.3 according to my system:
$ ruby --version
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin18]
$ which ruby
/Users/flaab/.rbenv/shims/ruby
Rbenv has 2.6.5 activated.
$ rbenv versions
system
* 2.6.5 (set by /Users/flaab/.ruby-version)
mruby-dev
But it recognizes the wrong one as well.
$ which -a ruby
/Users/flaab/.rbenv/shims/ruby
/usr/bin/ruby
My gem env is...
flaab#MBP-de-Arturo ~ $ gem env
RubyGems Environment:
- RUBYGEMS VERSION: 3.0.3
- RUBY VERSION: 2.6.5 (2019-10-01 patchlevel 114) [x86_64-darwin18]
- INSTALLATION DIRECTORY: /Users/flaab/.gem
- USER INSTALLATION DIRECTORY: /Users/flaab/.gem/ruby/2.6.0
- RUBY EXECUTABLE: /Users/flaab/.rbenv/versions/2.6.5/bin/ruby
- GIT EXECUTABLE: /usr/bin/git
- EXECUTABLE DIRECTORY: /Users/flaab/.gem/bin
- SPEC CACHE DIRECTORY: /Users/flaab/.gem/specs
- SYSTEM CONFIGURATION DIRECTORY: /Users/flaab/.rbenv/versions/2.6.5/etc
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-darwin-18
- GEM PATHS:
- /Users/flaab/.gem
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- "echo \"gem" => "--no-document\" > ~/.gemrc"
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /Users/flaab/.rbenv/versions/2.6.5/bin
- /opt/local/libexec/rbenv
- /Users/flaab/.rbenv/shims
- /usr/local/bin
- /opt/local/bin
- /opt/local/sbin
- /usr/local/bin
- /usr/bin
- /bin
- /usr/sbin
- /sbin
- /Users/flaab/bin
- /Users/flaab/.rbenv/shims
- /sw/bin
- /Users/flaab/.local/lib/npm/bin
- /Users/flaab/.composer/vendor/bin
How can I instruct gem to use the 2.6.5 version of ruby mentioned above?
Thanks in advance

Answer 1

To no avail. Ditched mac and went back to developing on debian. No issues.

Answer 2

Either run rbenv global 2.5.0 to set your global ruby or create a .ruby-version file in the app directory to instruct rbenv to use a specific version.
echo "2.5.0" >> .ruby-version and then try again.
Documentation

Answer 3

Do you have this already added to your .bash_profile ?
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"
If not add the above lines to the bottom of the file, then close and restart your terminal(s).
It looks like your EXECUTABLE DIRECTORY may not be set correctly. Try the following command:
rbenv shell 2.6.5
Also, make sure you're in a new empty directory and do
rbenv local 2.6.5
Then try rails command again
rails new blog