Different version of bundler required?

[MokeEire]

After following the Jekyll installation instructions, and installing Ruby, I am getting an error when I run jekyll serve -w:

Could not find 'bundler' (1.17.2) required by your C:/Users/.../my-reps/Gemfile.lock. (Gem::MissingSpecVersionError)
To update to the latest version installed on your system, run `bundle update --bundler`.
To install the missing version, run `gem install bundler:1.17.2`

I installed Ruby+Devkit 3.0 which may be the problem, but thought I would let you know in case this can be solved by updating the lock file. Thanks for the brilliant install instructions though, very helpful!

[MokeEire]

And now I am running into an error each package because the versions are different. Can I easily install the specific versions or try to serve the site with the versions I have installed (which seem to be more recently updated)?