title: Cocoapods. The spec did not pass validation : 'Cocoa/Cocoa.h' file not found but I have declared the Cocoa library
body: <p>One of the classes uses <code>#import &lt;Cocoa/Cocoa.h&gt;</code>. So, in my <code>Podspec</code>, I include the <code>framework</code> <code>Cocoa</code></p>
  
  <p>My <code>Podspec</code> is</p>
  
  <pre><code>Pod::Spec.new do |s|
    s.name         = "MyCBDLumberJack"
    s.version      = "0.0.1"
    s.summary      = "A customization of CocoaLumberJack"
    s.description  = &lt;&lt;-DESC
                    A customization of CocoaLumberJack
                    DESC
    s.author        = { "Me" =&gt; "me@gmail.com" }
    s.homepage      = "https://www.facebook.com/me"
    s.license = { :type =&gt; 'MIT',
                  :text =&gt;  &lt;&lt;-LICENSE
                    Copyright 2014. Me.
                            LICENSE
                }
    s.source       = { :git =&gt; 'https://me@bitbucket.org/me/mycbdlumberjack.git',
                      :tag =&gt;  "#{s.version}" }
    s.source_files  = 'MyCBDLumberJack/My Lumberjack/**/*.{h,m}'
    s.requires_arc = true
    s.framework = 'Cocoa'
    s.prefix_header_contents = '#import "DDLog.h"', 'static const int ddLogLevel = LOG_LEVEL_VERBOSE;'
    s.dependency 'CocoaLumberjack', '~&gt;1.8'
  end
  </code></pre>
  
  <p>Why is it so? How should I proceed?</p>