pod trunk push undefined method

Error

NoMethodError - undefined method `url' for nil:NilClass
/Library/Ruby/Gems/2.3.0/gems/cocoapods-trunk-1.4.0/lib/pod/command/trunk/push.rb:155:in `master_repo_url'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-trunk-1.4.0/lib/pod/command/trunk/push.rb:121:in `validate_podspec'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-trunk-1.4.0/lib/pod/command/trunk/push.rb:70:in `run'
/Library/Ruby/Gems/2.3.0/gems/claide-1.0.3/lib/claide/command.rb:334:in `run'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.8.0/lib/cocoapods/command.rb:52:in `run'
/Library/Ruby/Gems/2.3.0/gems/cocoapods-1.8.0/bin/pod:55:in `<top (required)>'
/usr/local/bin/pod:22:in `load'
/usr/local/bin/pod:22:in `<main>'

执行 pod install
重新建立cdn就可以了