[#180] check appledoc exit status

cocoapods.gemspec

@@ -29,6 +29,7 @@ Gem::Specification.new do |s|
                            "you are upgrading, first run: $ pod setup"
 
   s.add_runtime_dependency 'xcodeproj', '~> 0.1.0'
+  s.add_runtime_dependency 'popen4', '~> 0.1.2'
   s.add_development_dependency 'bacon', '~> 1.1'
 
   ## Make sure you can build the gem on older versions of RubyGems too:

lib/cocoapods/generator/documentation.rb

-require 'open3'
+require 'open4'
 
 module Pod
   module Generator
@@ -15,7 +15,7 @@ module Pod
       def initialize(pod)
         @pod = pod
         @specification = pod.specification
-        @target_path = pod.sandbox.root + "Documentation" + pod.name
+        @target_path = pod.sandbox.root + 'Documentation' + pod.name
         @options = pod.specification.documentation || {}
       end
 
@@ -36,7 +36,7 @@ module Pod
       end
 
       def description
-        @specification.description || "Generated by CocoaPods."
+        @specification.description || 'Generated by CocoaPods.'
       end
 
       def docs_id
@@ -49,7 +49,7 @@ module Pod
 
       def index_file
         @pod.chdir do
-          Dir.glob("README*", File::FNM_CASEFOLD).first
+          Dir.glob('README*', File::FNM_CASEFOLD).first
         end
       end
 
@@ -76,10 +76,12 @@ module Pod
           puts "[!] Skipping documentation generation because appledoc can't be found." if config.verbose?
           return
         end
+
         options = generate_appledoc_options
         options += ['--output', @target_path.to_s]
         options += ['--keep-intermediate-files']
         options += install ? ['-create-docset'] : ['--no-create-docset']
+
         @target_path.mkpath
         @pod.chdir do
           appledoc(options)
@@ -91,22 +93,19 @@ module Pod
         arguments += options
         arguments += ['--print-settings'] if config.verbose?
         arguments += files.map(&:to_s)
-        Open3.popen3('appledoc', *arguments) do |i, o, e|
+
+        process = Open4.popen4('appledoc', *arguments) do |_, _, output, error|
           if config.verbose?
-            puts o.read.chomp
-            puts e.read.chomp
-          else
-            # TODO: This is needed otherwise appledoc may not install the doc set
-            # This is a work around related to poor understanding of the IO class.
-            #
-            # I think we can use the non-block version here, which should read
-            # everything till the end and then return.
-            o.read
-            e.read
+            puts output.read.chomp
+            puts error.read.chomp
           end
         end
-      end
 
+        # appledoc exits with 1 if a warning was logged
+        if (process.exitstatus >= 2) && !config.silent?
+          puts "[!] Appledoc encountered an error. Run 'pod install --verbose' for details."
+        end
+      end
     end
   end
 end