For example:
foreman-rake puppet:import:puppet_classes[true,master]
From: /usr/share/foreman/lib/tasks/puppet.rake @ line 89 :

84:           end
    85:           exit 1
    86:         end
    87:        
    88:         require "pry" 
 => 89:         binding.pry
    90: 
    91:         puts "Changes: #{changes}" 
    92:         if changes["new"].empty? && changes["obsolete"].empty?
    93:           puts "No changes detected" unless args.batch
    94:           puts "debug"

Changes: {"new"=>{}, "obsolete"=>{}, "updated"=>{<any_data>}, "ignored"=>{}}

require change line 92: add changes["updated"].empty?
We are have problem with import new class parameters from puppet manifests, without this fix.