spec source validation for dummies

lib/cocoapods/command/spec.rb

@@ -296,7 +296,7 @@ def podspec_errors
           messages << "Missing summary"       unless spec.summary
           messages << "Missing homepage"      unless spec.homepage
           messages << "Missing author(s)"     unless spec.authors
-          messages << "Missing source"        unless spec.source
+          messages << "Missing or invalid source: #{spec.source}" unless source_valid?
 
           # attributes with multiplatform values
           return messages unless platform_valid?
@@ -315,6 +315,10 @@ def platform_valid?
           !spec.platform || [:ios, :osx].include?(spec.platform.name)
         end
 
+        def source_valid?
+          spec.source && !spec.source =~ /http:\/\/EXAMPLE/
+        end
+
         def paths_starting_with_a_slash_errors
           messages = []
           %w[source_files resources clean_paths].each do |accessor|