Problem

After upgrading to Mac OS Big Sur, I saw this error I haven’t seen before:

➜  bundle exec jekyll serve
Could not find commonmarker-0.17.13 in any of the sources
Run `bundle install` to install missing gems.

So I ran bundle install but it didn’t seem to work either. An excerpt from the terminal output:

➜  bundle install
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

An error occurred while installing commonmarker (0.17.13), and Bundler cannot continue.
Make sure that `gem install commonmarker -v '0.17.13' --source 'https://rubygems.org/'` succeeds before bundling.

An error occurred while installing unf_ext (0.0.7.7), and Bundler cannot continue.
Make sure that `gem install unf_ext -v '0.0.7.7' --source 'https://rubygems.org/'` succeeds before bundling.

An error occurred while installing rdiscount (2.2.0.2), and Bundler cannot continue.
Make sure that `gem install rdiscount -v '2.2.0.2' --source 'https://rubygems.org/'` succeeds before bundling.

Solution

After some research and trial and error, I found this precious answer in Stack Overflow that it is due to the Ruby version that is not compatible with Big Sur and it should be at least 2.7. So I checked Ruby releases and decided to go with one of the most recent releases: 2.7.2.

Anyway, steps I think worked:

  1. Check Ruby version 
     ➜  ruby -v
 ruby 2.6.3p62 (2019-04-16 revision 67580) [universal.x86_64-darwin20]
  2. Install Ruby Version Manager (rvm) 
     ➜  curl -sSL https://raw.githubusercontent.com/rvm/rvm/master/binscripts/rvm-installer | bash -s stable
  3. Install 2.7.2 version using rvm 
     ➜  rvm install "ruby-2.7.2"
  4. Check Ruby version again 
     ➜  ruby -v
 ruby 2.7.2p137 (2020-10-01 revision 5445e04352) [x86_64-darwin20]
  5. Bundle install 
     ➜  bundle install
  6. Run bundle 
     ➜  bundle exec jekyll serve

And it worked!

Some other things I tried

  1. Installing Ruby through Homebrew: didn’t solve the issue but I don’t know if this actually and eventually helped or not.

     ➜  brew install ruby

  2. Installing the latest version of Ruby (ref) using rvm: didn’t update the version for some reason.

     ➜  rvm install ruby@latest