Cocoapods: Unable to find a specification for `Firebase/Core`
<p>I have this in podfile:</p>

<pre><code>pod 'Firebase/Core'
pod 'Firebase/Messaging'
</code></pre>

<p>but getting this error:</p>

<blockquote>
  <p>[!] Unable to find a specification for <code>Firebase/Core</code></p>
</blockquote>

<p>i tried with <code>pod 'Firebase'</code> still can't find it.</p>

<p>Podfile:</p>

<pre><code># Uncomment this line to define a global platform for your project
# platform :ios, '8.0'
# Uncomment this line if you're using Swift
use_frameworks!

target 'caffetouch manager' do
    pod 'Firebase/Core'
    pod 'Firebase/Messaging'
    pod 'Alamofire', '~&gt; 4.0.0'
    pod 'AlamofireNetworkActivityIndicator', '~&gt; 2.0.1'
    pod 'IQKeyboardManagerSwift', '~&gt; 4.0.6'
    pod 'MZFormSheetPresentationController', '~&gt; 2.4.2'
    pod 'Kingfisher', '~&gt; 3.1.3'
    pod "GMStepper"
    pod 'DKImagePickerController', '~&gt; 3.4.0'
    pod 'Siren', '~&gt; 1.0.2'
    pod 'Eureka', '~&gt; 2.0.0-beta.1'
    pod 'SwiftyJSON'
    pod 'ObjectMapper', '~&gt; 2.1'
    pod 'NVActivityIndicatorView'
    pod 'SwiftDate', '~&gt; 4.0.5'
    pod 'SimpleAlert' '~&gt; 2.0.1'

    pod 'BTNavigationDropdownMenu', :git =&gt; 'https://github.com/PhamBaTho/BTNavigationDropdownMenu.git', :branch =&gt; 'swift-3.0'
    pod 'ENSwiftSideMenu', :git =&gt; 'https://github.com/evnaz/ENSwiftSideMenu.git', :branch =&gt; 'master'
    pod 'SkyFloatingLabelTextField', git: "https://github.com/MLSDev/SkyFloatingLabelTextField.git", branch: "swift3"
end


post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['SWIFT_VERSION'] = '3.0'
    end
  end
end
</code></pre>