Installation messed up with Ruby: Unable to install jekyll - ruby

Question

I was trying to setup a GitHub Page using Jekyll, which rely on Ruby (like here). Unfortunately, I think I kind of messed up with the installation (after a few sudo apt-get install ruby-full and sudo apt-get remove ruby-full ...)
Right now, I am stuck with an old version of Ruby (I think) on my computer that I am not able to update. Here is the state of my system right now:
$ ruby -v
ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-linux-gnu]
$ gem -v
3.1.2
$ gem install jekyll
ERROR: Error installing jekyll:
The last version of sass-embedded (~> 1.54) to support your Ruby & RubyGems was 1.58.0. Try installing it with `gem install sass-embedded -v 1.58.0` and then running the current command again
sass-embedded requires RubyGems version >= 3.3.22. The current RubyGems version is 3.1.2. Try 'gem update --system' to update RubyGems itself.
$ gem update --system
Updating rubygems-update
Successfully installed rubygems-update-3.4.6
Parsing documentation for rubygems-update-3.4.6
Done installing documentation for rubygems-update after 0 seconds
Parsing documentation for rubygems-update-3.4.6
Done installing documentation for rubygems-update after 0 seconds
Installing RubyGems 3.4.6
Traceback (most recent call last):
5: from setup.rb:22:in `<main>'
4: from setup.rb:22:in `require'
3: from /home/jarret/gems/gems/rubygems-update-3.4.6/lib/rubygems.rb:1332:in `<top (required)>'
2: from /home/jarret/gems/gems/rubygems-update-3.4.6/lib/rubygems.rb:1332:in `require'
1: from /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb:49:in `<top (required)>'
/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb:50:in `<class:Specification>': undefined method `rubyforge_project=' for class `Gem::Specification' (NameError)
3: from setup.rb:22:in `<main>'
2: from setup.rb:22:in `require'
1: from /home/jarret/gems/gems/rubygems-update-3.4.6/lib/rubygems.rb:1328:in `<top (required)>'
/home/jarret/gems/gems/rubygems-update-3.4.6/lib/rubygems.rb:1342:in `rescue in <top (required)>': undefined method `rubyforge_project=' for class `Gem::Specification' (NameError)
Loading the /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb file caused an error. This file is owned by your OS, not by rubygems upstream. Please find out which OS package this file belongs to and follow the guidelines from your OS to report the problem and ask for help.
$ gem env
RubyGems Environment:
- RUBYGEMS VERSION: 3.1.2
- RUBY VERSION: 2.7.0 (2019-12-25 patchlevel 0) [x86_64-linux-gnu]
- INSTALLATION DIRECTORY: /home/jarret/gems
- USER INSTALLATION DIRECTORY: /home/jarret/.gem/ruby/2.7.0
- RUBY EXECUTABLE: /usr/bin/ruby2.7
- GIT EXECUTABLE: /usr/bin/git
- EXECUTABLE DIRECTORY: /home/jarret/gems/bin
- SPEC CACHE DIRECTORY: /home/jarret/.gem/specs
- SYSTEM CONFIGURATION DIRECTORY: /etc
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-linux
- GEM PATHS:
- /home/jarret/gems
- /home/jarret/.gem/ruby/2.7.0
- /var/lib/gems/2.7.0
- /usr/lib/ruby/gems/2.7.0
- /usr/share/rubygems-integration/2.7.0
- /usr/share/rubygems-integration/all
- /usr/lib/x86_64-linux-gnu/rubygems-integration/2.7.0
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /home/jarret/gems/bin
- /home/jarret/miniconda3/condabin
- /usr/local/sbin
- /usr/local/bin
- /usr/sbin
- /usr/bin
- /sbin
- /bin
- /usr/games
- /usr/local/games
- /snap/bin
- /opt/fiji/Fiji.app
I've tried many remove/install, I've tried updated gem, ruby. Nothing unlocked me so far.

Answer 1

Try to replace ruby3.0, sass1.58 is too advanced and may not be compatible with ruby2.7.
Please follow these steps and run the command.
rvm install 3.0
rvm use 3.0.0 -default
rvm -v
rvm gemset update
gem install jekyll
jekyll -v