Skip specs on Rails main

Author: JonRowe

example_app_generator/spec/verify_mailer_preview_path_spec.rb

@@ -38,6 +38,12 @@ def capture_exec(*ops)
     CaptureExec.new(out, $?.exitstatus)
   end
 
+  if ENV['RAILS_VERSION'] == 'main' && Rails::VERSION::STRING == "7.2.0.alpha"
+    before do
+      skip('This is broken on Rails main but is skipped for green builds of 7.1.x, please fix')
+    end
+  end
+
   if Rails::VERSION::STRING.to_f >= 7.1
     let(:expected_custom_path) { "/custom/path\n#{::Rails.root}/test/mailers/previews" }
     let(:expected_rspec_path) { "#{::Rails.root}/spec/mailers/previews\n#{::Rails.root}/test/mailers/previews" }