/tmp >gem list measured
*** LOCAL GEMS ***
measured (2.3.0)
/tmp >irb
irb [2.4.0] (tmp)$ require "measured"
NameError: uninitialized constant #<Class:Measured::Measurable>::Forwardable
from /Users/sshaw/.rvm/gems/ruby-2.4.0/gems/measured-2.3.0/lib/measured/measurable.rb:65:in `singleton class'
from /Users/sshaw/.rvm/gems/ruby-2.4.0/gems/measured-2.3.0/lib/measured/measurable.rb:64:in `<class:Measurable>'
from /Users/sshaw/.rvm/gems/ruby-2.4.0/gems/measured-2.3.0/lib/measured/measurable.rb:1:in `<top (required)>'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:68:in `require'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:68:in `require'
from /Users/sshaw/.rvm/gems/ruby-2.4.0/gems/measured-2.3.0/lib/measured/base.rb:46:in `<top (required)>'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:68:in `require'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:68:in `require'
from /Users/sshaw/.rvm/gems/ruby-2.4.0/gems/measured-2.3.0/lib/measured.rb:1:in `<top (required)>'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:133:in `require'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:133:in `rescue in require'
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/lib/ruby/site_ruby/2.4.0/rubygems/core_ext/kernel_require.rb:40:in `require'
from (irb):1
from /Users/sshaw/.rvm/rubies/ruby-2.4.0/bin/irb:11:in `<main>'
https://github.com/Shopify/measured/blob/7b59a925715ec381db5ec69de03b87096dd8586f/lib/measured/measurable.rb#L65