After reading up on the bundler project about "conservative updating" this, bundle_nice.sh above, appears to be the suggested workflow for updating Just the Gems You Have To:
gem list -r --all $Xto get the latest version of whatever gem you want.- Edit Gemfile to add a new '=' version constraint for that gem.
- Edit Gemfile.lock to relax the locked constraint for that gem, up to the new version. Dependencies (
gem specification $X -v $version) will be updated bybundle installandbundle checkin the Gemfile.lock automatically. - Run
bundle installto conservatively update the dependency graph, and Gemfile.lock. - Remove the constraint from the Gemfile, and run
bundle checkto update the Gemfile.lock with the removed constraint without installing new gems. - whew.
Below is a log of those actions, along with git diff interspersed for clarity.