kcu is a shell alias for knife cookbook upload, in case that's not obvious

Knife output

opus:iacez-chef larrywright$ kcu ruby-shadow
DEBUG: Using configuration from /Users/larrywright/repos/client/iacez-chef/.chef/knife.rb
INFO: Saving ruby-shadow
INFO: Validating ruby files
DEBUG: Testing /Users/larrywright/repos/client/iacez-chef/.chef/../cookbooks/ruby-shadow/files/default/shadow-1.4.1/extconf.rb for syntax errors...
DEBUG: sh(ruby -c /Users/larrywright/repos/client/iacez-chef/.chef/../cookbooks/ruby-shadow/files/default/shadow-1.4.1/extconf.rb)
DEBUG: Testing /Users/larrywright/repos/client/iacez-chef/.chef/../cookbooks/ruby-shadow/recipes/default.rb for syntax errors...
DEBUG: sh(ruby -c /Users/larrywright/repos/client/iacez-chef/.chef/../cookbooks/ruby-shadow/recipes/default.rb)
INFO: Validating templates
INFO: Syntax OK
DEBUG: Generating metadata
INFO: Generating Metadata
DEBUG: No /Users/larrywright/repos/client/iacez-chef/cookbooks/ruby-shadow/metadata.rb found; skipping!
DEBUG: Signing the request as iacez
DEBUG: Sending HTTP Request via POST to api.opscode.com:443/organizations/iacez/sandboxes
INFO: Uploading files
INFO: Uploading /Users/larrywright/repos/client/iacez-chef/cookbooks/ruby-shadow/files/default/shadow-1.4.1/MANIFEST (checksum hex = 5396ec4fadafe39fe266c016f6e2e0d1) to https://s3.amazonaws.com/opscode-platform-production-data/organization-09df261f59c44cc4acca9be19149c4dd/sandbox-6fabf52dbc434b079a8da2e67680a361/checksum-5396ec4fadafe39fe266c016f6e2e0d1?AWSAccessKeyId=AKIAJOZTD2N26S7W6APA&Expires=1294377502&Signature=V%2F1Et9dJLOl5%2BqklXlJozIns0Cc%3D
INFO: Uploading /Users/larrywright/repos/client/iacez-chef/cookbooks/ruby-shadow/files/default/shadow-1.4.1/shadow.c (checksum hex = d6d965c1ae8e44843539e672b10e93b2) to https://s3.amazonaws.com/opscode-platform-production-data/organization-09df261f59c44cc4acca9be19149c4dd/sandbox-6fabf52dbc434b079a8da2e67680a361/checksum-d6d965c1ae8e44843539e672b10e93b2?AWSAccessKeyId=AKIAJOZTD2N26S7W6APA&Expires=1294377502&Signature=tfU9wDekQ3q75zjNH9K0XOvnr6o%3D
INFO: Uploading /Users/larrywright/repos/client/iacez-chef/cookbooks/ruby-shadow/files/default/shadow-1.4.1/README (checksum hex = 6533337a8ff6eaa1c8a046f1d83ebfcd) to https://s3.amazonaws.com/opscode-platform-production-data/organization-09df261f59c44cc4acca9be19149c4dd/sandbox-6fabf52dbc434b079a8da2e67680a361/checksum-6533337a8ff6eaa1c8a046f1d83ebfcd?AWSAccessKeyId=AKIAJOZTD2N26S7W6APA&Expires=1294377502&Signature=Aew%2BmySprxdBBqgQs4XlyEHE8Lg%3D
/Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/protocol.rb:135:in `sysread': Connection reset by peer (Errno::ECONNRESET)
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/protocol.rb:135:in `rbuf_fill'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/timeout.rb:62:in `timeout'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/timeout.rb:93:in `timeout'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/protocol.rb:134:in `rbuf_fill'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/protocol.rb:116:in `readuntil'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/protocol.rb:126:in `readline'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/http.rb:2024:in `read_status_line'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/http.rb:2013:in `read_new'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/http.rb:1050:in `__request__'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/net_http_ext.rb:15:in `request'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/request.rb:167:in `transmit'
	from /Users/larrywright/.rvm/rubies/ruby-1.8.7-p249/lib/ruby/1.8/net/http.rb:543:in `start'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/request.rb:166:in `transmit'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/request.rb:60:in `execute'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/request.rb:31:in `execute'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/rest-client-1.6.1/lib/restclient/resource.rb:72:in `put'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/cookbook_uploader.rb:51:in `upload_cookbook'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/cookbook_uploader.rb:30:in `each'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/cookbook_uploader.rb:30:in `upload_cookbook'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife/cookbook_upload.rb:67:in `run'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife/cookbook_upload.rb:65:in `each'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife/cookbook_upload.rb:65:in `run'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife/cookbook_upload.rb:80:in `humanize_auth_exceptions'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife/cookbook_upload.rb:53:in `run'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/knife.rb:127:in `run'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/lib/chef/application/knife.rb:121:in `run'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/gems/chef-0.9.12/bin/knife:25
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/bin/knife:19:in `load'
	from /Users/larrywright/.rvm/gems/ruby-1.8.7-p249/bin/knife:19