Ruby error

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

I'm trying to run something written in ruby that uses ruby-nokogiri.

I'm getting errors like this:

/usr/pkg/lib/ruby/2.7.0/rubygems/dependency.rb:313:in `to_specs': Could 
not find 'mini_portile2' (~> 2.4.0) - did find: [mini_portile2-2.5.0] 
(Gem::MissingSpecVersionError)
Checked in 
'GEM_PATH=/u10/rjs/.gem/ruby/2.7.0:/usr/pkg/lib/ruby/gems/2.7.0', 
execute `gem env` for more information

Have tried ruby 2.5, 2.6 and 2.7 and get the same.