Explain how this is completely broken

Gemfile

@@ -12,10 +12,6 @@ else
   gem 'activerecord', ENV['AR']
 end
 
-git 'https://github.com/gregmolnar/ransack', branch: 'fix-polymorphic-joins' do
-  gem 'polyamorous'
-end
-
 gem 'bump'
 
 group :test do

baby_squeel.gemspec

@@ -20,10 +20,10 @@ Gem::Specification.new do |spec|
   spec.files = Dir.glob('{lib/**/*,*.{md,txt,gemspec}}')
 
   spec.add_dependency 'activerecord', '>= 4.2.0'
-  spec.add_dependency 'polyamorous', '~> 2.1.1'
+  spec.add_dependency 'polyamorous', '~> 2.3.0'
   spec.add_dependency 'join_dependency', '~> 0.1.4'
 
-  spec.add_development_dependency 'bundler', '~> 1.11'
+  spec.add_development_dependency 'bundler', '~> 2'
   spec.add_development_dependency 'rake', '~> 10.0'
   spec.add_development_dependency 'rspec', '~> 3.4.0'
   spec.add_development_dependency 'sqlite3', '~> 1.3.6'

lib/baby_squeel/join_dependency.rb

@@ -37,9 +37,15 @@ def initialize(relation)
       def find_alias(associations)
         join_association = find_join_association(associations)
 
+        # NOTE: Below is a hack. It does not work. In previous
+        # versions of Active Record, `#table` would ALWAYS return
+        # an instance of Arel::Table.
         if join_association.table
           join_association.table
         else
+          # This literally does not work. This will often
+          # give you the wrong Arel::Table instance, which
+          # causes aliases in the query to be wrong.
           join_association.base_klass.arel_table
         end
       end