This is a technical thing that you should not have to do during normal use. It might be of interest if you want to update the GitHub pages / Jekyll software to a later version or experiment with extensions.

Start by making modifications to Gemfile as desired.

Then enter a special environment designed just for running bundler:

nix-shell -A bundler

From here you can run various commands:

# rewrite Gemfile.lock, applying any changes to Gemfile
bundle lock

# update gems to latest versions
bundle update

# update just one gem
bundle update some-gem

Notes:

  • The only platform in Gemfile.lock should be “ruby”. Remove the others if they show up.
  • After any changes, make sure to remove the hash from our_gemset.nix before running nix-shell again.