Helpful exception when reading version information with merge conflict

related to https://github.com/CocoaPods/CocoaPods/issues/1853, https://github.com/CocoaPods/CocoaPods/issues/2065, https://github.com/CocoaPods/CocoaPods/issues/2056 etc.

CHANGELOG.md

@@ -11,6 +11,10 @@ To install or update CocoaPods see this [guide](http://docs.cocoapods.org/guides
   [Fabio Pelosin][irrationalfab]
   [Xcodeproj#105](https://github.com/CocoaPods/Xcodeproj/pull/150)
 
+* Show a helpful error message when reading version information with merge conflict
+  [Samuel E. Giddins][segiddins]
+  [#1853](https://github.com/CocoaPods/CocoaPods/issues/1853)
+
 ## 0.32.1
 
 ##### Bug Fixes

lib/cocoapods/sources_manager.rb

@@ -259,7 +259,16 @@ module Pod
       def version_information(dir)
         require 'yaml'
         yaml_file  = dir + 'CocoaPods-version.yml'
-        yaml_file.exist? ? YAML.load_file(yaml_file) : {}
+        return {} unless yaml_file.exist?
+        begin
+          yaml = Pathname.new(yaml_file).read
+          YAMLHelper.load(yaml)
+        rescue Informative => e
+          raise Informative, "There was an error reading '#{yaml_file}'.\n" \
+            'Please consult http://blog.cocoapods.org/' \
+            'Repairing-Our-Broken-Specs-Repository/ ' \
+            'for more information.'
+        end
       end
 
       public

spec/unit/sources_manager_spec.rb

@@ -14,6 +14,18 @@ def set_up_test_repo_for_update
   config.repos_dir = SpecHelper.tmp_repos_path
 end
 
+def merge_conflict_version_yaml
+  text = <<-VERSION.strip_heredoc
+    ---
+    <<<<<<< HEAD
+    min: 0.18.1
+    =======
+    min: 0.29.0
+    >>>>>>> 8365d0ad18508175bbde31b9dd2bdaf1be49214f
+    last: 0.29.0
+  VERSION
+end
+
 module Pod
   describe SourcesManager do
 
@@ -146,6 +158,12 @@ module Pod
         e.message.should.match /Update CocoaPods/
       end
 
+      it 'raises when reading version information with merge conflict' do
+        Pathname.any_instance.stubs(:read).returns(merge_conflict_version_yaml)
+        e = lambda { SourcesManager.version_information(SourcesManager.master_repo_dir) }.should.raise Informative
+        e.message.should.match /Repairing-Our-Broken-Specs-Repository/
+      end
+
       it "returns whether a repository is compatible" do
         SourcesManager.stubs(:version_information).returns({ 'min' => '0.0.1' })
         SourcesManager.repo_compatible?('stub').should.be.true