[PodTarget] Enforce that specs are given

lib/cocoapods/target/pod_target.rb

@@ -28,6 +28,7 @@ module Pod
     # @param [Bool] scoped @see scoped
     #
     def initialize(specs, target_definitions, sandbox, scoped = false)
+      raise "Can't initialize a PodTarget without specs!" if specs.nil? || specs.empty?
       @specs = specs
       @target_definitions = target_definitions
       @sandbox = sandbox

spec/unit/installer_spec.rb

@@ -463,8 +463,9 @@ module Pod
         end
 
         it 'sets the deployment target for the whole project' do
-          pod_target_ios = PodTarget.new([], nil, config.sandbox)
-          pod_target_osx = PodTarget.new([], nil, config.sandbox)
+          spec = fixture_spec('banana-lib/BananaLib.podspec')
+          pod_target_ios = PodTarget.new([spec], nil, config.sandbox)
+          pod_target_osx = PodTarget.new([spec], nil, config.sandbox)
           pod_target_ios.stubs(:platform).returns(Platform.new(:ios, '6.0'))
           pod_target_osx.stubs(:platform).returns(Platform.new(:osx, '10.8'))
           aggregate_target_ios = AggregateTarget.new(nil, config.sandbox)