ArgumentError while following Extensions in Developer's Guide

[davidsherline]

Hello, I am following the Extensions tutorial in the Developer's Guide. While setting sale_price for a product variant in the Rails console, the call to variant.save produces an ArgumentError (see below). I've tried using various versions of Rails between 4.1.2 and 4.1.6 and each produces the same error. Please advise how I might continue the tutorial as expected. Thanks!

THE ERROR:

ArgumentError: A copy of Spree::Preferences::Configuration has been removed from the module tree but is still active!
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:465:in load_missing_constant' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:180:inconst_missing'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/spree_core-2.3.3/app/models/spree/preferences/configuration.rb:32:in preferences' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/spree_core-2.3.3/app/models/spree/preferences/preferable_class_methods.rb:13:inblock in preference'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/spree_core-2.3.3/app/models/spree/preferences/preferable.rb:43:in get_preference' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/spree_core-2.3.3/app/models/spree/variant.rb:24:inblock in class:Variant'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/builder/association.rb:64:in instance_exec' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/builder/association.rb:64:inblock in initialize'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:149:in instance_exec' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:149:ineval_scope'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:112:in block (2 levels) in add_constraints' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:111:ineach'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:111:in block in add_constraints' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:69:ineach'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:69:in each_with_index' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.1.6/lib/active_record/associations/association_scope.rb:69:inadd_constraints'
... 68 levels...
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:69:in console' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands/commands_tasks.rb:40:inrun_command!'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.1.6/lib/rails/commands.rb:17:in <top (required)>' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/polyglot-0.3.5/lib/polyglot.rb:65:inrequire'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/polyglot-0.3.5/lib/polyglot.rb:65:in require' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:inblock in require'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:in load_dependency' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:247:inrequire'
from /Users/David/Sites/tutorials/spree/mystore/bin/rails:8:in <top (required)>' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:241:inload'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:241:in block in load' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:232:inload_dependency'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.1.6/lib/active_support/dependencies.rb:241:in load' from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:inrequire'
from /usr/local/var/rbenv/versions/2.1.3/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'

[JDutil]

@Hypsol I'm not able to reproduce this error. You'll have to provide the information requested in our Contributing Guidelines including steps to reproduce the error.

It sounds related to Rails 4.1 and spring though, and likely will go away if you exit and reenter the console. There is another similar issue that I consider this to be a duplicate of with some more information: #5104