Can't install gems using asdf - ruby

Question

So I'm switching to a project that is using ruby. They use asdf as a package manager
I’m having trouble installing the gems, I’m using zsh and I’m thinking there might be an issue with the paths
Running gem install bundler outputs: You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory.
ruby -v
outputs: ruby 2.3.7p456 (2018-03-28 revision 63024) [universal.x86_64-darwin18]
which ruby
output: /usr/bin/ruby
And I tried setting a global version for ruby with asdf global ruby 2.5.3 but that doesn’t seem to change the version
This is my gem environment:
RubyGems Environment:
- RUBYGEMS VERSION: 2.5.2.3
- RUBY VERSION: 2.3.7 (2018-03-28 patchlevel 456) [universal.x86_64-darwin18]
- INSTALLATION DIRECTORY: /Library/Ruby/Gems/2.3.0
- USER INSTALLATION DIRECTORY: /Users/carlos.grijalva/.gem/ruby/2.3.0
- RUBY EXECUTABLE: /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby
- EXECUTABLE DIRECTORY: /usr/local/bin
- SPEC CACHE DIRECTORY: /Users/carlos.grijalva/.gem/specs
- SYSTEM CONFIGURATION DIRECTORY: /Library/Ruby/Site
- RUBYGEMS PLATFORMS:
- ruby
- universal-darwin-18
- GEM PATHS:
- /Library/Ruby/Gems/2.3.0
- /Users/carlos.grijalva/.gem/ruby/2.3.0
- /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/gems/2.3.0
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /Users/carlos.grijalva/.asdf/shims
- /Users/carlos.grijalva/.asdf/bin
- /Users/carlos.grijalva/bin
- /usr/local/bin
- /usr/local/bin
- /usr/bin
- /bin
- /usr/sbin
- /sbin

Answer 1

It sounds like you may need to add the relevant lines to your .zshrc so asdf shims get recognized. You can find the instructions here
For macOS & zsh the correct lines to append to .zshrc are:
echo -e '\n. $HOME/.asdf/asdf.sh' >> ~/.zshrc
echo -e '\n. $HOME/.asdf/completions/asdf.bash' >> ~/.zshrc
After doing so, either source ~/.zshrc or restart your terminal