pod install 错误 .cocoapods/repos `open': No such file or directory

wuyamingdeMBP:DNApp yaming$ pod install
Analyzing dependencies
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/pathname.rb:422:in `open': No such file or directory - /Users/yaming/.cocoapods/repos (Errno::ENOENT)
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/pathname.rb:422:in `foreach'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/pathname.rb:422:in `children'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/lib/cocoapods/sources_manager.rb:63:in `all'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/lib/cocoapods/user_interface/error_report.rb:130:in `repo_information'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/lib/cocoapods/user_interface/error_report.rb:34:in `report'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/lib/cocoapods/command.rb:58:in `report_error'
from /Library/Ruby/Gems/2.0.0/gems/claide-0.7.0/lib/claide/command.rb:300:in `handle_exception'
from /Library/Ruby/Gems/2.0.0/gems/claide-0.7.0/lib/claide/command.rb:274:in `rescue in run'
from /Library/Ruby/Gems/2.0.0/gems/claide-0.7.0/lib/claide/command.rb:264:in `run'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/lib/cocoapods/command.rb:45:in `run'
from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.35.0/bin/pod:43:in `<top (required)>'
from /usr/bin/pod:23:in `load'
from /usr/bin/pod:23:in `<main>'

wuyamingdeMBP:DNApp yaming$ pod setup
Setting up CocoaPods master repo

CocoaPods 0.36.0.beta.2 is available.
To update use: `gem install cocoapods --pre`
[!] This is a test version we'd love you to try.

For more information see http://blog.cocoapods.org and the CHANGELOG for this version http://git.io/BaH8pQ. 
Setup completed

Analyzing dependencies

CocoaPods 0.36.0.beta.2 is available.
To update use: `gem install cocoapods --pre`
[!] This is a test version we'd love you to try.

For more information see http://blog.cocoapods.org and the CHANGELOG for this version http://git.io/BaH8pQ. 
Downloading dependencies
Installing Canvas (0.1.2)
Generating Pods project
Integrating client project

[!] From now on use `DNApp.xcworkspace`.