cocoapods - 同じ podspec ファイルで、サブスペック 'B' からサブスペック 'A' への依存関係を宣言するにはどうすればよいですか?

Question

以下のように、podspec: 'mypodspecfile.podspec' でサブスペック 'B' からサブスペック 'A' への依存関係を宣言する方法を見つけようとしています。

Pod::Spec.new do |s|
  s.name         = "MyLib-SDK"
  s.version      = "1.0"
  s.summary      = "My Library"
  s.homepage     = "http://myhomepage.com"

  s.ios.deployment_target = "8.0"
  s.ios.frameworks = "Foundation", "UIKit", "SystemConfiguration", "Security", "CoreTelephony", "WebKit"

  s.source       = { :git => "https://github.com/myhome/ios-project.git", :tag => "1.0" }

  s.subspec 'MyLibrary-A' do |libOne|
    libOne.source_files  = "Headers", "Headers/**/*.h"
    libOne.exclude_files = "Headers/Exclude"
    libOne.resources = "SharedAssets/*"

    libOne.libraries = "z","sqlite3" #Zlib for gzip, sqlite3 for event store
    libOne.vendored_library = "libMyLibrary_A.a"
  end

  s.subspec 'MyLibrary-B' do |libTwo|
    libTwo.source_files  = "Headers", "Headers/**/*.h"
    libTwo.exclude_files = "Headers/Exclude"
    libTwo.resources = "SharedAssets/*"
    libTwo.dependency 'MyLibrary-A'  <-- doesn't seem to be working here!!

    libTwo.libraries = "sqlite3" # sqlite3 for db
    libTwo.vendored_library = "libMyLibrary_B.a"
  end

 end

私が実行すると：

$pod spec lint mypodspecfile.podspec --verbose

-ERROR | [iOS] unknown: Encountered an unknown error (Unable to find a specification for MyLibrary-A depended upon by MyLibrary-B

どんな助けでも大歓迎です。ありがとうございます！