ruby 3.4.3 undefined method 'zero?' for nil

[yk-eta]

scenario:
trying to mock with rspec for stub_request(:head, /storage.googleapis.com/).to_return(status: 200, body: "", headers: {}) on model update field

error message:
undefined method 'zero?' for nil

stacktrace:

/gems/carrierwave-3.1.2/lib/carrierwave/storage/fog.rb:320:in 'CarrierWave::Storage::Fog::File#empty?'
/gems/activesupport-8.0.2/lib/active_support/core_ext/object/blank.rb:19:in 'Object#blank?'
/gems/carrierwave-3.1.2/lib/carrierwave/uploader/proxy.rb:11:in 'CarrierWave::Uploader::Proxy#blank?'
/gems/activemodel-8.0.2/lib/active_model/validator.rb:153:in 'block in ActiveModel::EachValidator#validate'
/gems/activemodel-8.0.2/lib/active_model/validator.rb:151:in 'Array#each'
/gems/activemodel-8.0.2/lib/active_model/validator.rb:151:in 'ActiveModel::EachValidator#validate'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:384:in 'block in ActiveSupport::Callbacks::CallTemplate::ObjectCall#make_lambda'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:178:in 'block in ActiveSupport::Callbacks::Filters::Before#call'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:668:in 'block (2 levels) in ActiveSupport::Callbacks::CallbackChain#default_terminator'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:667:in 'Kernel#catch'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:667:in 'block in ActiveSupport::Callbacks::CallbackChain#default_terminator'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:179:in 'ActiveSupport::Callbacks::Filters::Before#call'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:559:in 'block in ActiveSupport::Callbacks::CallbackSequence#invoke_before'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:559:in 'Array#each'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:559:in 'ActiveSupport::Callbacks::CallbackSequence#invoke_before'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:108:in 'ActiveSupport::Callbacks#run_callbacks'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:913:in 'ActiveRecord::Base#_run_validate_callbacks'
/gems/activemodel-8.0.2/lib/active_model/validations.rb:474:in 'ActiveModel::Validations#run_validations!'
/gems/activemodel-8.0.2/lib/active_model/validations/callbacks.rb:115:in 'block in ActiveModel::Validations::Callbacks#run_validations!'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:109:in 'ActiveSupport::Callbacks#run_callbacks'
/gems/activesupport-8.0.2/lib/active_support/callbacks.rb:913:in 'ActiveRecord::Base#_run_validation_callbacks'
/gems/activemodel-8.0.2/lib/active_model/validations/callbacks.rb:115:in 'ActiveModel::Validations::Callbacks#run_validations!'
/gems/activemodel-8.0.2/lib/active_model/validations.rb:365:in 'ActiveModel::Validations#valid?'
/gems/activerecord-8.0.2/lib/active_record/validations.rb:71:in 'ActiveRecord::Validations#valid?'
/gems/activerecord-8.0.2/lib/active_record/validations.rb:91:in 'ActiveRecord::Validations#perform_validations'
/gems/activerecord-8.0.2/lib/active_record/validations.rb:54:in 'ActiveRecord::Validations#save!'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:365:in 'block in ActiveRecord::Transactions#save!'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:417:in 'block (2 levels) in ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:357:in 'ActiveRecord::ConnectionAdapters::DatabaseStatements#transaction'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:413:in 'block in ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:412:in 'ActiveRecord::ConnectionAdapters::ConnectionPool#with_connection'
/gems/activerecord-8.0.2/lib/active_record/connection_handling.rb:310:in 'ActiveRecord::ConnectionHandling#with_connection'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:409:in 'ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:365:in 'ActiveRecord::Transactions#save!'
/gems/activerecord-8.0.2/lib/active_record/suppressor.rb:56:in 'ActiveRecord::Suppressor#save!'
/gems/activerecord-8.0.2/lib/active_record/persistence.rb:579:in 'block in ActiveRecord::Persistence#update!'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:417:in 'block (2 levels) in ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:357:in 'ActiveRecord::ConnectionAdapters::DatabaseStatements#transaction'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:413:in 'block in ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:412:in 'ActiveRecord::ConnectionAdapters::ConnectionPool#with_connection'
/gems/activerecord-8.0.2/lib/active_record/connection_handling.rb:310:in 'ActiveRecord::ConnectionHandling#with_connection'
/gems/activerecord-8.0.2/lib/active_record/transactions.rb:409:in 'ActiveRecord::Transactions#with_transaction_returning_status'
/gems/activerecord-8.0.2/lib/active_record/persistence.rb:577:in 'ActiveRecord::Persistence#update!'

ruby: 3.4.3
rails: 8.0.2
carrierwave: 3.1.2

[yk-eta]

added content_length on stub_request solved the error

stub_request(:head, /storage.googleapis.com/).to_return(status: 200, body: "1", headers: {
      content_length: 1
})

[yk-eta]

btw, the real connection error is fired with Fog.mock!, is it valid?