[Specification] Provide a meaningful error message if a subspec can't be found.

CHANGELOG.md

@@ -11,8 +11,10 @@
 - Added `pod update` that installs the dependencies of the Podfile ignoring the contents of the `Podfile.lock`. [#131](https://github.com/CocoaPods/CocoaPods/issues/131)
 - Added `pod outdated` that show the pods that would be installed by `pod update`.
 - Added `:local` option for dependencies. [#458](https://github.com/CocoaPods/CocoaPods/issues/458) [#415](https://github.com/CocoaPods/CocoaPods/issues/415) [#156](https://github.com/CocoaPods/CocoaPods/issues/156)
-- Added a meaningful error message if a podspec can’t be found in the root of an external source. [#385](https://github.com/CocoaPods/CocoaPods/issues/385)  [#338](https://github.com/CocoaPods/CocoaPods/issues/338)  [#337](https://github.com/CocoaPods/CocoaPods/issues/337)
-- Added a meaningful error message for unrecognized commands/arguments.
+- Added a meaningful error messages:
+  - in case a podspec couldn’t be found in the root of an external source. [#385](https://github.com/CocoaPods/CocoaPods/issues/385)  [#338](https://github.com/CocoaPods/CocoaPods/issues/338)  [#337](https://github.com/CocoaPods/CocoaPods/issues/337)
+  - in case a unrecognized commands/argument is provided.
+  - in case a subspec name is misspelled.
 
 ###### Bug fixes
 

lib/cocoapods/specification.rb

@@ -393,14 +393,14 @@ module Pod
       # Remove this spec's name from the beginning of the name we’re looking for
       # and take the first component from the remainder, which is the spec we need
       # to find now.
-      remainder = name[self.name.size+1..-1].split('/')
-      subspec_name = remainder.shift
+      remainder = name[self.name.size+1..-1]
+      raise Informative, "Unable to find a specification named `#{name}' in `#{pod_name}'." unless remainder
+      subspec_name = remainder.split('/').shift
       subspec = subspecs.find { |s| s.name == "#{self.name}/#{subspec_name}" }
+      raise Informative, "Unable to find a specification named `#{name}' in `#{pod_name}'." unless subspec
       # If this was the last component in the name, then return the subspec,
       # otherwise we recursively keep calling subspec_by_name until we reach the
       # last one and return that
-
-      raise Informative, "Unable to find a subspec named `#{name}'." unless subspec
       remainder.empty? ? subspec : subspec.subspec_by_name(name)
     end