Merge pull request #2637 from CocoaPods/resolver

Molinillo

Merge pull request #2637 from CocoaPods/resolver
Molinillo
0a6e8a17 · Samuel E. Giddins · 28b95e88 · d0d72ea7 · 0a6e8a17 · 0a6e8a17
Commit 0a6e8a17 authored Oct 24, 2014 by Samuel E. Giddins
16 changed files
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,13 @@ To install or update CocoaPods see this [guide](http://docs.cocoapods.org/guides
 ## Master
-##### Enhacements
+##### Breaking
+* Attempts to resolve circular dependencies will now raise an exception.  
+  [Samuel Giddins](https://github.com/segiddins)
+  [Molinillo#6](https://github.com/CocoaPods/Molinillo/issues/6)
+##### Enhancements
 * The `pod push` has been removed as it has been deprecated in favour of `pod
  repo push` in CocoaPods 0.33.  
@@ -15,6 +21,26 @@ To install or update CocoaPods see this [guide](http://docs.cocoapods.org/guides
  [Marius Rackwitz](https://github.com/mrackwitz)
  [#2461](https://github.com/CocoaPods/CocoaPods/issues/2461)
+* The `Resolver` has been completely rewritten to use
+  [Molinillo](https://github.com/CocoaPods/Molinillo), an iterative dependency
+  resolution algorithm that automatically resolves version conflicts.
+  The order in which dependencies are declared in the `Podfile` no longer has
+  any effect on the resolution process.  
+  [Samuel Giddins](https://github.com/segiddins)
+  [#978](https://github.com/CocoaPods/CocoaPods/issues/978)
+  [#2002](https://github.com/CocoaPods/CocoaPods/issues/2002)
+* Implicit dependencies are now locked, so simply running `pod install` will not
+  cause them to be updated when they shouldn't be.  
+  [Samuel Giddins](https://github.com/segiddins)
+  [#2318](https://github.com/CocoaPods/CocoaPods/issues/2318)
+  [#2506](https://github.com/CocoaPods/CocoaPods/issues/2506)
+* Pre-release versions are only considered in the resolution process when there
+  are dependencies that explicitly reference pre-release requirements.  
+  [Samuel Giddins](https://github.com/segiddins)
+  [#1489](https://github.com/CocoaPods/CocoaPods/issues/1489)
 ##### Bug Fixes
 * Do not try to clone spec-repos in `/`.  

--- a/Gemfile
+++ b/Gemfile
@@ -12,12 +12,13 @@ gemspec
 group :development do
  cp_gem 'claide',               'CLAide'
-  cp_gem 'cocoapods-core',       'Core'
+  cp_gem 'cocoapods-core',       'Core', 'resolver'
  cp_gem 'cocoapods-downloader', 'cocoapods-downloader'
  cp_gem 'cocoapods-plugins',    'cocoapods-plugins'
  cp_gem 'cocoapods-trunk',      'cocoapods-trunk'
  cp_gem 'cocoapods-try',        'cocoapods-try'
  cp_gem 'xcodeproj',            'Xcodeproj'
+  cp_gem 'molinillo',            'Molinillo'
  gem 'bacon'
  gem 'mocha'

--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,8 +7,8 @@ GIT
 GIT
  remote: https://github.com/CocoaPods/Core.git
-  revision: 99748b5b9fa8fe6541218f1752c0379589c7a6ee
+  revision: 802401562948abf9f4f417ace4cd8e9bb8b08859
-  branch: master
+  branch: resolver
  specs:
    cocoapods-core (0.34.4)
      activesupport (>= 3.2.15)
@@ -16,6 +16,13 @@ GIT
      json_pure (~> 1.8)
      nap (~> 0.8.0)
+GIT
+  remote: https://github.com/CocoaPods/Molinillo.git
+  revision: 3e27234148022ba1455a9228e7b710314204d4c5
+  branch: master
+  specs:
+    molinillo (0.0.1)
 GIT
  remote: https://github.com/CocoaPods/Xcodeproj.git
  revision: ff7c70da5f5082eef47bb248012b69c76f6c6e54
@@ -71,6 +78,7 @@ PATH
      colored (~> 1.2)
      escape (~> 0.0.4)
      json_pure (~> 1.8)
+      molinillo (~> 0)
      nap (~> 0.8)
      open4 (~> 1.3)
      xcodeproj (~> 0.19.4)
@@ -174,6 +182,7 @@ DEPENDENCIES
  mime-types (< 2.0)
  mocha
  mocha-on-bacon
+  molinillo!
  prettybacon
  pry
  rake

--- a/cocoapods.gemspec
+++ b/cocoapods.gemspec
@@ -34,6 +34,7 @@ Gem::Specification.new do |s|
  s.add_runtime_dependency 'cocoapods-plugins',    '~> 0.3.1'
  s.add_runtime_dependency 'cocoapods-try',        '~> 0.4.1'
  s.add_runtime_dependency 'cocoapods-trunk',      '~> 0.3.1'
+  s.add_runtime_dependency 'molinillo',            '~> 0'
  s.add_runtime_dependency 'colored',       '~> 1.2'
  s.add_runtime_dependency 'escape',        '~> 0.0.4'

--- a/lib/cocoapods/command.rb
+++ b/lib/cocoapods/command.rb
 require 'colored'
 require 'claide'
+require 'molinillo/errors'
+module Molinillo
+  class ResolverError
+    include CLAide::InformativeError
+  end
+end
 module Pod
  class PlainInformative

--- a/lib/cocoapods/installer/analyzer.rb
+++ b/lib/cocoapods/installer/analyzer.rb
@@ -8,6 +8,8 @@ module Pod
      autoload :SandboxAnalyzer, 'cocoapods/installer/analyzer/sandbox_analyzer'
+      autoload :LockingDependencyAnalyzer, 'cocoapods/installer/analyzer/locking_dependency_analyzer'
      # @return [Sandbox] The sandbox where the Pods should be installed.
      #
      attr_reader :sandbox
@@ -149,17 +151,13 @@ module Pod
          pods_state = nil
          UI.section 'Finding Podfile changes' do
            pods_by_state = lockfile.detect_changes_with_podfile(podfile)
-            pods_by_state.dup.each do |state, full_names|
-              pods = full_names.map { |fn| Specification.root_name(fn) }.uniq
-              pods_by_state[state] = pods
-            end
            pods_state = SpecsState.new(pods_by_state)
            pods_state.print
          end
          pods_state
        else
          state = SpecsState.new
-          state.added.concat(podfile.dependencies.map(&:root_name).uniq)
+          state.added.concat(podfile.dependencies.map(&:name).uniq)
          state
        end
      end
@@ -231,21 +229,17 @@ module Pod
      # is in update mode, to prevent it from upgrading the Pods that weren't
      # changed in the {Podfile}.
      #
-      # @return [Array<Dependency>] the dependencies generate by the lockfile
+      # @return [Molinillo::DependencyGraph<Dependency>] the dependencies
-      #         that prevent the resolver to update a Pod.
+      #         generated by the lockfile that prevent the resolver to update
+      #         a Pod.
      #
      def generate_version_locking_dependencies
-        if update_mode == :all
+        if update_mode == :all || !lockfile
-          []
+          LockingDependencyAnalyzer.unlocked_dependency_graph
        else
-          locking_pods = result.podfile_state.unchanged
+          pods_to_update = result.podfile_state.changed + result.podfile_state.deleted
-          if update_mode == :selected
+          pods_to_update += update[:pods] if update_mode == :selected
-            # If selected Pods should been updated, filter them out of the list
+          LockingDependencyAnalyzer.generate_version_locking_dependencies(lockfile, pods_to_update)
-            locking_pods = locking_pods.select { |pod| !update[:pods].include?(pod) }
-          end
-          locking_pods.map do |pod|
-            lockfile.dependencies_to_lock_pod_named(pod)
-          end.flatten
        end
      end
@@ -281,9 +275,9 @@ module Pod
          if update_mode == :selected
            pods_to_fetch += update[:pods]
          end
-          deps_to_fetch = deps_with_external_source.select { |dep| pods_to_fetch.include?(dep.root_name) }
+          deps_to_fetch = deps_with_external_source.select { |dep| pods_to_fetch.include?(dep.name) }
-          deps_to_fetch_if_needed = deps_with_external_source.select { |dep| result.podfile_state.unchanged.include?(dep.root_name) }
+          deps_to_fetch_if_needed = deps_with_external_source.select { |dep| result.podfile_state.unchanged.include?(dep.name) }
-          deps_to_fetch += deps_to_fetch_if_needed.select { |dep| sandbox.specification(dep.root_name).nil? || !dep.external_source[:local].nil? || !dep.external_source[:path].nil? || !sandbox.pod_dir(dep.root_name).directory? }
+          deps_to_fetch += deps_to_fetch_if_needed.select { |dep| sandbox.specification(dep.name).nil? || !dep.external_source[:local].nil? || !dep.external_source[:path].nil? || !sandbox.pod_dir(dep.name).directory? }
        end
        unless deps_to_fetch.empty?
@@ -352,7 +346,7 @@ module Pod
      # @!group Analysis internal products
-      # @return [Array<Dependency>] the dependencies generate by the lockfile
+      # @return [Molinillo::DependencyGraph<Dependency>] the dependencies generated by the lockfile
      #         that prevent the resolver to update a Pod.
      #
      attr_reader :locked_dependencies
@@ -604,7 +598,7 @@ module Pod
      #
      class SpecsState
        # @param  [Hash{Symbol=>String}] pods_by_state
-        #         The **root** name of the pods grouped by their state
+        #         The name of the pods grouped by their state
        #         (`:added`, `:removed`, `:changed` or `:unchanged`).
        #
        def initialize(pods_by_state = nil)
@@ -656,12 +650,9 @@ module Pod
        # @param  [Symbol]
        #         the state of the Pod.
        #
-        # @raise  If there is an attempt to add the name of a subspec.
-        #
        # @return [void]
        #
        def add_name(name, state)
-          raise '[Bug] Attempt to add subspec to the pods state' if name.include?('/')
          send(state) << name
        end
      end

--- a/lib/cocoapods/installer/analyzer/locking_dependency_analyzer.rb
+++ b/lib/cocoapods/installer/analyzer/locking_dependency_analyzer.rb
+require 'molinillo/dependency_graph'
+module Pod
+  class Installer
+    class Analyzer
+      # Generates dependencies that require the specific version of the Pods
+      # that haven't changed in the {Lockfile}.
+      module LockingDependencyAnalyzer
+        # Generates dependencies that require the specific version of the Pods
+        # that haven't changed in the {Lockfile}.
+        #
+        # These dependencies are passed to the {Resolver}, unless the installer
+        # is in update mode, to prevent it from upgrading the Pods that weren't
+        # changed in the {Podfile}.
+        #
+        # @return [Molinillo::DependencyGraph<Dependency>] the dependencies
+        #         generated by the lockfile that prevent the resolver to update
+        #         a Pod.
+        #
+        def self.generate_version_locking_dependencies(lockfile, pods_to_update)
+          dependency_graph = Molinillo::DependencyGraph.new
+          if lockfile
+            explicit_dependencies = lockfile.to_hash['DEPENDENCIES'] || []
+            explicit_dependencies.each do |string|
+              dependency = Dependency.new(string)
+              dependency_graph.add_root_vertex(dependency.name, nil)
+            end
+            pods = lockfile.to_hash['PODS'] || []
+            pods.each do |pod|
+              add_to_dependency_graph(pod, [], dependency_graph)
+            end
+            pods_to_update.each { |u| dependency_graph.detach_vertex_named(u) }
+          end
+          dependency_graph
+        end
+        # Generates a completely 'unlocked' dependency graph.
+        #
+        # @return [Molinillo::DependencyGraph<Dependency>] an empty dependency
+        #         graph
+        #
+        def self.unlocked_dependency_graph
+          Molinillo::DependencyGraph.new
+        end
+        private
+        def self.add_child_vertex_to_graph(dependency_string, parents, dependency_graph)
+          dependency = Dependency.from_string(dependency_string)
+          dependency_graph.add_child_vertex(dependency.name, parents.empty? ? dependency : nil, parents, nil)
+          dependency
+        end
+        def self.add_to_dependency_graph(object, parents, dependency_graph)
+          case object
+          when String
+            add_child_vertex_to_graph(object, parents, dependency_graph)
+          when Hash
+            object.each do |key, value|
+              dependency = add_child_vertex_to_graph(key, parents, dependency_graph)
+              value.each { |v| add_to_dependency_graph(v, [dependency.name], dependency_graph) }
+            end
+          end
+        end
+      end
+    end
+  end
+end
--- a/lib/cocoapods/resolver.rb
+++ b/lib/cocoapods/resolver.rb
+require 'molinillo'
+require 'cocoapods/resolver/lazy_specification'
 module Pod
  # The resolver is responsible of generating a list of specifications grouped
  # by target for a given Podfile.
  #
-  # @todo Its current implementation is naive, in the sense that it can't do full
-  #   automatic resolves like Bundler:
-  #   [how-does-bundler-bundle](http://patshaughnessy.net/2011/9/24/how-does-bundler-bundle)
-  #
-  # @todo Another limitation is that the order of the dependencies matter. The
-  #   current implementation could create issues, for example, if a
-  #   specification is loaded for a target definition and later for another
-  #   target is set in head mode. The first specification will not be in head
-  #   mode.
-  #
-  #
  class Resolver
    # @return [Sandbox] the Sandbox used by the resolver to find external
    #         dependencies.
@@ -58,23 +50,12 @@ module Pod
    #         definition.
    #
    def resolve
-      @cached_sets     = {}
+      dependencies = @podfile.target_definition_list.map(&:dependencies).flatten
-      @cached_specs    = {}
+      @cached_sets = {}
-      @specs_by_target = {}
+      @activated = Molinillo::Resolver.new(self, self).resolve(dependencies, locked_dependencies)
-      target_definitions = podfile.target_definition_list
-      target_definitions.each do |target|
-        title = "Resolving dependencies for target `#{target.name}' " \
-          "(#{target.platform})"
-        UI.section(title) do
-          @loaded_specs = []
-          find_dependency_specs(podfile, target.dependencies, target)
-          specs = cached_specs.values_at(*@loaded_specs).sort_by(&:name)
-          specs_by_target[target] = specs
-        end
-      end
      specs_by_target
+    rescue Molinillo::ResolverError => e
+      raise Informative, e.message
    end
    # @return [Hash{Podfile::TargetDefinition => Array<Specification>}]
@@ -82,113 +63,235 @@ module Pod
    #
    # @note   The returned specifications can be subspecs.
    #
-    attr_reader :specs_by_target
+    def specs_by_target
+      @specs_by_target ||= begin
+        specs_by_target = {}
+        podfile.target_definition_list.each do |target|
+          specs = target.dependencies.map(&:name).map do |name|
+            node = @activated.vertex_named(name)
+            (node.recursive_successors << node).to_a
+          end
+          specs_by_target[target] = specs.
+            flatten.
+            map(&:payload).
+            uniq.
+            sort_by(&:name).
+            each do |spec|
+              validate_platform(spec, target)
+              sandbox.store_head_pod(spec.name) if spec.version.head
+            end
+        end
+        specs_by_target
+      end
+    end
    #-------------------------------------------------------------------------#
-    private
+    public
-    # !@ Resolution context
+    # @!group Specification Provider
-    # @return [Hash<String => Set>] A cache that keeps tracks of the sets
+    include Molinillo::SpecificationProvider
-    #         loaded by the resolution process.
+    # Returns (and caches) the specification that satisfy the given dependency.
    #
-    # @note   Sets store the resolved dependencies and return the highest
+    # @return [Array<Specification>] the specifications that satisfy the given
-    #         available specification found in the sources. This is done
+    #   `dependency`.
-    #         globally and not per target definition because there can be just
-    #         one Pod installation, so different version of the same Pods for
-    #         target definitions are not allowed.
    #
-    attr_accessor :cached_sets
+    # @param  [Dependency] dependency the dependency that is being searched for.
+    #
+    def search_for(dependency)
+      @search ||= {}
+      @search[dependency] ||= begin
+        specs = find_cached_set(dependency).
+          all_specifications.
+          select { |s| dependency.requirement.satisfied_by? s.version }.
+          map { |s| s.subspec_by_name(dependency.name, false) }
-    # @return [Hash<String => Specification>] The loaded specifications grouped
+        specs.
-    #         by name.
+          reverse.
+          each { |s| s.version.head = dependency.head? }
+      end
+      @search[dependency].dup
+    end
+    # Returns the dependencies of `specification`.
+    #
+    # @return [Array<Specification>] all dependencies of `specification`.
+    #
+    # @param  [Specification] specification the specification whose own
+    #         dependencies are being asked for.
    #
-    attr_accessor :cached_specs
+    def dependencies_for(specification)
+      specification.all_dependencies.map do |dependency|
+        if dependency.root_name == Specification.root_name(specification.name)
+          Dependency.new(dependency.name, specification.version)
+        else
+          dependency
+        end
+      end
+    end
-    #-------------------------------------------------------------------------#
+    # Returns the name for the given `dependency`.
+    #
+    # @return [String] the name for the given `dependency`.
+    #
+    # @param  [Dependency] dependency the dependency whose name is being
+    #         queried.
+    #
+    def name_for(dependency)
+      dependency.name
+    end
-    private
+    # @return [String] the user-facing name for a {Podfile}.
+    #
+    def name_for_explicit_dependency_source
+      'Podfile'
+    end
-    # @!group Private helpers
+    # @return [String] the user-facing name for a {Lockfile}.
+    #
+    def name_for_locking_dependency_source
+      'Podfile.lock'
+    end
-    # Resolves recursively the dependencies of a specification and stores them
+    # Determines whether the given `requirement` is satisfied by the given
-    # in the @cached_specs ivar.
+    # `spec`, in the context of the current `activated` dependency graph.
    #
-    # @param  [Podfile, Specification, #to_s] dependent_spec
+    # @return [Boolean] whether `requirement` is satisfied by `spec` in the
-    #         the specification whose dependencies are being resolved. Used
+    #         context of the current `activated` dependency graph.
-    #         only for UI purposes.
    #
-    # @param  [Array<Dependency>] dependencies
+    # @param  [Dependency] requirement the dependency in question.
-    #         the dependencies of the specification.
    #
-    # @param  [TargetDefinition] target_definition
+    # @param  [Molinillo::DependencyGraph] activated the current dependency
-    #         the target definition that owns the specification.
+    #         graph in the resolution process.
    #
-    # @note   If there is a locked dependency with the same name of a
+    # @param  [Specification] spec the specification in question.
-    #         given dependency the locked one is used in place of the
-    #         dependency of the specification. In this way it is possible to
-    #         prevent the update of the version of installed pods not changed
-    #         in the Podfile.
    #
-    # @note   The recursive process checks if a dependency has already been
+    def requirement_satisfied_by?(requirement, activated, spec)
-    #         loaded to prevent an infinite loop.
+      existing_vertices = activated.vertices.values.select do |v|
+        Specification.root_name(v.name) ==  requirement.root_name
+      end
+      existing = existing_vertices.map(&:payload).compact.first
+      requirement_satisfied =
+        if existing
+          existing.version == spec.version && requirement.requirement.satisfied_by?(spec.version)
+        else
+          requirement.requirement.satisfied_by? spec.version
+        end
+      requirement_satisfied && !(spec.version.prerelease? && existing_vertices.flat_map(&:requirements).none?(&:prerelease?))
+    end
+    # Sort dependencies so that the ones that are easiest to resolve are first.
+    # Easiest to resolve is (usually) defined by:
+    #   1) Is this dependency already activated?
+    #   2) How relaxed are the requirements?
+    #   3) Are there any conflicts for this dependency?
+    #   4) How many possibilities are there to satisfy this dependency?
    #
-    # @note   The set class merges all (of all the target definitions) the
+    # @return [Array<Dependency>] the sorted dependencies.
-    #         dependencies and thus it keeps track of whether it is in head
-    #         mode or from an external source because {Dependency#merge}
-    #         preserves this information.
    #
-    # @return [void]
+    # @param  [Array<Dependency>] dependencies the unsorted dependencies.
    #
-    def find_dependency_specs(dependent_spec, dependencies, target_definition)
+    # @param  [Molinillo::DependencyGraph] activated the dependency graph of
-      dependencies.each do |dependency|
+    #         currently activated specs.
-        locked_dep = locked_dependencies.find { |ld| ld.name == dependency.name }
+    #
-        dependency = locked_dep if locked_dep
+    # @param  [{String => Array<Conflict>}] conflicts the current conflicts.
+    #
+    def sort_dependencies(dependencies, activated, conflicts)
+      dependencies.sort_by do |dependency|
+        name = name_for(dependency)
+        [
+          activated.vertex_named(name).payload ? 0 : 1,
+          dependency.prerelease? ? 0 : 1,
+          conflicts[name] ? 0 : 1,
+          search_for(dependency).count,
+        ]
+      end
+    end
-        UI.message("- #{dependency}", '', 2) do
+    #-------------------------------------------------------------------------#
-          set = find_cached_set(dependency, dependent_spec)
-          set.required_by(dependency, dependent_spec.to_s)
-          if (paths = set.specification_paths_for_version(set.required_version)).length > 1
+    public
-            UI.warn "Found multiple specifications for #{dependency}:\n" \
-              "- #{paths.join("\n")}"
-          end
-          unless @loaded_specs.include?(dependency.name)
+    # @!group Resolver UI
-            spec = set.specification.subspec_by_name(dependency.name)
-            @loaded_specs << spec.name
-            cached_specs[spec.name] = spec
-            validate_platform(spec, target_definition)
-            if dependency.head? || sandbox.head_pod?(spec.name)
-              spec.version.head = true
-              sandbox.store_head_pod(spec.name)
-            end
-            spec_dependencies = spec.all_dependencies(target_definition.platform)
+    include Molinillo::UI
-            find_dependency_specs(spec, spec_dependencies, target_definition)
-          end
+    include Config::Mixin
-        end
-      end
+    # The UI object the resolver should use for displaying user-facing output.
+    #
+    # @return [UserInterface] the normal CocoaPods UI object.
+    #
+    def output
+      UI
    end
+    # Called before resolution starts. We print out `Resolving dependencies` in
+    # the analyzer, so here we just want to print out a starting `.` in verbose
+    # mode.
+    #
+    # @return [Void]
+    #
+    def before_resolution
+      UI.print '.' if config.verbose
+    end
+    # Called after resolution ends. We don't want to {#indicate_progress}
+    # unless in verbose mode, so we only use the default implementation then.
+    #
+    # @return [Void]
+    #
+    def after_resolution
+      super if config.verbose
+    end
+    # Called during resolution to indicate progress.
+    # We only use the default implementation in verbose mode.
+    #
+    # @return [Void]
+    #
+    def indicate_progress
+      super if config.verbose
+    end
+    #-------------------------------------------------------------------------#
+    private
+    # !@ Resolution context
+    # @return [Hash<String => Set>] A cache that keeps tracks of the sets
+    #         loaded by the resolution process.
+    #
+    # @note   Sets store the resolved dependencies and return the highest
+    #         available specification found in the sources. This is done
+    #         globally and not per target definition because there can be just
+    #         one Pod installation, so different version of the same Pods for
+    #         target definitions are not allowed.
+    #
+    attr_accessor :cached_sets
+    #-------------------------------------------------------------------------#
+    private
+    # @!group Private helpers
    # @return [Set] Loads or returns a previously initialized set for the Pod
    #               of the given dependency.
    #
    # @param  [Dependency] dependency
    #         The dependency for which the set is needed.
    #
-    # @param  [#to_s] dependent_spec
-    #         the specification whose dependencies are being resolved. Used
-    #         only for UI purposes.
-    #
    # @return [Set] the cached set for a given dependency.
    #
-    def find_cached_set(dependency, dependent_spec)
+    def find_cached_set(dependency)
      name = dependency.root_name
      unless cached_sets[name]
        if dependency.external_source
-          spec = sandbox.specification(dependency.root_name)
+          spec = sandbox.specification(name)
          unless spec
            raise StandardError, '[Bug] Unable to find the specification ' \
              "for `#{dependency}`."
@@ -199,8 +302,7 @@ module Pod
        end
        cached_sets[name] = set
        unless set
-          raise Informative, 'Unable to find a specification for ' \
+          raise Molinillo::NoSuchDependencyError.new(dependency) # rubocop:disable Style/RaiseArgs
-            "`#{dependency}` depended upon by #{dependent_spec}."
        end
      end
      cached_sets[name]

--- a/lib/cocoapods/resolver/lazy_specification.rb
+++ b/lib/cocoapods/resolver/lazy_specification.rb
+module Pod
+  class Specification
+    class Set
+      class LazySpecification < BasicObject
+        attr_reader :name, :version, :source
+        def initialize(name, version, source)
+          @name = name
+          @version = version
+          @source = source
+        end
+        def method_missing(method, *args, &block)
+          specification.send(method, *args, &block)
+        end
+        def subspec_by_name(name = nil, raise_if_missing = true)
+          if !name || name == self.name
+            self
+          else
+            specification.subspec_by_name(name, raise_if_missing)
+          end
+        end
+        def specification
+          @specification ||= source.specification(name, version)
+        end
+      end
+      class External
+        def all_specifications
+          [specification]
+        end
+      end
+      def all_specifications
+        @all_specifications ||= begin
+          sources_by_version = {}
+          versions_by_source.each do |source, versions|
+            versions.each { |v| (sources_by_version[v] ||= []) << source }
+            sources_by_version
+          end
+          duplicate_versions = sources_by_version.select { |_version, sources| sources.count > 1 }
+          duplicate_versions.each do |version, sources|
+            UI.warn "Found multiple specifications for `#{name} (#{version})`:\n" +
+              sources.
+                map { |s| s.specification_path(name, version) }.
+                map { |v| "- #{v}" }.join("\n")
+          end
+          versions_by_source.map do |source, versions|
+            versions.map { |version| LazySpecification.new(name, version, source) }
+          end.flatten
+        end
+      end
+    end
+  end
+end
--- a/lib/cocoapods/sandbox.rb
+++ b/lib/cocoapods/sandbox.rb
@@ -219,6 +219,7 @@ module Pod
    # @return [Nil] if the podspec is not stored.
    #
    def specification_path(name)
+      name = Specification.root_name(name)
      path = specifications_root + "#{name}.podspec"
      if path.exist?
        path
@@ -378,7 +379,7 @@ module Pod
    end
    # @return [Hash{String=>String}] The path of the Pods with a local source
-    #         grouped by their name.
+    #         grouped by their root name.
    #
    # @todo   Rename (e.g. `pods_with_local_path`)
    #

--- a/cocoapods-integration-specs @ afc3bdb8
+++ b/cocoapods-integration-specs @ afc3bdb8
-Subproject commit ae87cdaa7f0c96ad246ddd804a08bc4260018548
+Subproject commit afc3bdb824e79fe2f99361aa9b4525cda4cc95d1
--- a/master @ b6e1c242
+++ b/master @ b6e1c242
-Subproject commit b0f4e85738f1f911e32e2914b39e9acdce7c7ed9
+Subproject commit b6e1c2429964b4e47b344958572930e15ffbbcea
--- a/spec/functional/command/spec_spec.rb
+++ b/spec/functional/command/spec_spec.rb
@@ -226,13 +226,13 @@ module Pod
      it 'cats the given podspec' do
        lambda { command('spec', 'cat', 'AFNetworking').run }.should.not.raise
-        UI.output.should.include fixture('spec-repos/master/Specs/AFNetworking/2.3.1/AFNetworking.podspec.json').read
+        UI.output.should.include fixture('spec-repos/master/Specs/AFNetworking/2.4.1/AFNetworking.podspec.json').read
      end
      it 'cats the first podspec from all podspecs' do
        UI.next_input = "1\n"
        run_command('spec', 'cat', '--show-all', 'AFNetworking')
-        UI.output.should.include fixture('spec-repos/master/Specs/AFNetworking/2.3.1/AFNetworking.podspec.json').read
+        UI.output.should.include fixture('spec-repos/master/Specs/AFNetworking/2.4.1/AFNetworking.podspec.json').read
      end
    end
@@ -292,7 +292,7 @@ module Pod
        it 'returns the path of the specification with the given name' do
          path = @sut.send(:get_path_of_spec, 'AFNetworking')
-          path.should == fixture('spec-repos') + 'master/Specs/AFNetworking/2.3.1/AFNetworking.podspec.json'
+          path.should == fixture('spec-repos') + 'master/Specs/AFNetworking/2.4.1/AFNetworking.podspec.json'
        end
      end

--- a/spec/functional/user_interface_spec.rb
+++ b/spec/functional/user_interface_spec.rb
@@ -48,7 +48,7 @@ module Pod
      output = UI.output
      output.should.include? 'Author:   Robbie Hanson'
      output.should.include? 'License:  BSD'
-      output.should.include? 'Platform: iOS - OS X'
+      output.should.include? 'Platform: iOS 5.0 - OS X 10.7'
      output.should.include? 'Watchers: 318'
      output.should.include? 'Forks:    42'
      output.should.include? 'Pushed:   more than a year ago'

--- a/spec/unit/installer/analyzer_spec.rb
+++ b/spec/unit/installer/analyzer_spec.rb
@@ -13,7 +13,7 @@ def create_analyzer
  end
  hash = {}
-  hash['PODS'] = ['JSONKit (1.4)', 'NUI (0.2.0)', 'SVPullToRefresh (0.4)']
+  hash['PODS'] = ['JSONKit (1.5pre)', 'NUI (0.2.0)', 'SVPullToRefresh (0.4)']
  hash['DEPENDENCIES'] = %w(JSONKit NUI SVPullToRefresh)
  hash['SPEC CHECKSUMS'] = {}
  hash['COCOAPODS'] = Pod::VERSION
@@ -52,10 +52,10 @@ module Pod
      it 'computes the state of the Podfile respect to the Lockfile' do
        state = @analyzer.analyze.podfile_state
-        state.added.should     == %w(AFNetworking libextobjc)
+        state.added.should     == %w(AFNetworking libextobjc/EXTKeyPathCoding)
-        state.changed.should   == ['JSONKit']
+        state.changed.should   == %w()
-        state.unchanged.should == ['SVPullToRefresh']
+        state.unchanged.should == %w(JSONKit SVPullToRefresh)
-        state.deleted.should   == ['NUI']
+        state.deleted.should   == %w(NUI)
      end
      #--------------------------------------#
@@ -131,13 +131,35 @@ module Pod
      it 'locks the version of the dependencies which did not change in the Podfile' do
        @analyzer.analyze
-        @analyzer.send(:locked_dependencies).map(&:to_s).should == ['SVPullToRefresh (= 0.4)']
+        @analyzer.send(:locked_dependencies).map(&:payload).map(&:to_s).
+          should == ['JSONKit (= 1.5pre)', 'SVPullToRefresh (= 0.4)']
      end
      it 'does not lock the dependencies in update mode' do
        @analyzer.update = true
        @analyzer.analyze
-        @analyzer.send(:locked_dependencies).map(&:to_s).should == []
+        @analyzer.send(:locked_dependencies).to_a.map(&:payload).should == []
+      end
+      #--------------------------------------#
+      it 'takes into account locked implicit dependencies' do
+        podfile = Podfile.new do
+          platform :ios, '8.0'
+          xcodeproj 'SampleProject/SampleProject'
+          pod 'ARAnalytics/Mixpanel'
+        end
+        hash = {}
+        hash['PODS'] = ['ARAnalytics/CoreIOS (2.8.0)', {'ARAnalytics/Mixpanel (2.8.0)' => ['ARAnlytics/CoreIOS', 'Mixpanel']}, 'Mixpanel (2.5.1)']
+        hash['DEPENDENCIES'] = %w(ARAnalytics/Mixpanel)
+        hash['SPEC CHECKSUMS'] = {}
+        hash['COCOAPODS'] = Pod::VERSION
+        lockfile = Pod::Lockfile.new(hash)
+        analyzer = Installer::Analyzer.new(config.sandbox, podfile, lockfile)
+        analyzer.analyze.specifications.
+          find { |s| s.name == 'Mixpanel' }.
+          version.to_s.should == '2.5.1'
      end
      #--------------------------------------#

--- a/spec/unit/resolver_spec.rb
+++ b/spec/unit/resolver_spec.rb
 require File.expand_path('../../spec_helper', __FILE__)
+def dependency_graph_from_array(locked_dependencies)
+  locked_dependencies.reduce(Molinillo::DependencyGraph.new) do |graph, dep|
+    graph.add_root_vertex(dep.name, dep)
+    graph
+  end
+end
+def empty_graph
+  Molinillo::DependencyGraph.new
+end
 module Pod
  describe Resolver do
    describe 'In general' do
@@ -8,7 +19,7 @@ module Pod
          platform :ios
          pod 'BlocksKit', '1.5.2'
        end
-        locked_deps = [Dependency.new('BlocksKit', '1.5.2')]
+        locked_deps = dependency_graph_from_array([Dependency.new('BlocksKit', '1.5.2')])
        @resolver = Resolver.new(config.sandbox, @podfile, locked_deps, SourcesManager.all)
      end
@@ -21,7 +32,8 @@ module Pod
      end
      it 'returns the locked dependencies' do
-        @resolver.locked_dependencies.should == [Dependency.new('BlocksKit', '1.5.2')]
+        @resolver.locked_dependencies.
+          should == dependency_graph_from_array([Dependency.new('BlocksKit', '1.5.2')])
      end
      #--------------------------------------#
@@ -55,11 +67,20 @@ module Pod
          platform :ios
          pod 'Reachability', :podspec => podspec
        end
-        resolver = Resolver.new(config.sandbox, podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
        resolver.resolve
        specs = resolver.specs_by_target.values.flatten
        specs.map(&:to_s).should == ['Reachability (3.0.0)']
      end
+      it 'resolves an empty podfile' do
+        @podfile = Podfile.new do
+          platform :ios
+        end
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
+        specs = resolver.resolve.values.flatten.map(&:to_s).sort
+        specs.should == []
+      end
    end
    #-------------------------------------------------------------------------#
@@ -70,7 +91,7 @@ module Pod
          platform :ios, '6.0'
          pod 'BlocksKit', '1.5.2'
        end
-        @resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        @resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
      end
      it 'cross resolves dependencies' do
@@ -80,11 +101,53 @@ module Pod
          pod 'AFQuickLookView', '=  0.1.0' # requires  'AFNetworking', '>= 0.9.0'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should == ['AFNetworking (0.9.1)', 'AFQuickLookView (0.1.0)']
      end
+      it 'resolves basic conflicts' do
+        @podfile = Podfile.new do
+          platform :ios, '7.0'
+          pod 'RestKit' # latest version (0.23.3) requires 'AFNetworking', '~> 1.3.0'
+          pod 'AFNetworking', '~> 1.2.0'
+        end
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
+        specs = resolver.resolve.values.flatten.map(&:to_s).sort
+        specs.should == ['AFNetworking (1.2.1)', 'RestKit (0.20.1)',
+                         'RestKit/Core (0.20.1)', 'RestKit/CoreData (0.20.1)',
+                         'RestKit/Network (0.20.1)', 'RestKit/ObjectMapping (0.20.1)',
+                         'RestKit/Support (0.20.1)', 'SOCKit (1.1)', 'TransitionKit (1.1.0)']
+      end
+      it 'resolves three-way conflicts' do
+        @podfile = Podfile.new do
+          platform :ios, '7.0'
+          pod 'AFAmazonS3Client' # latest version (2.0.0) requires 'AFNetworking', '~> 2.0'
+          pod 'CargoBay' # latest version (2.1.0) requires 'AFNetworking', '~> 2.2'
+          pod 'AFOAuth2Client' # latest version (0.1.2) requires 'AFNetworking', '~> 1.3'
+        end
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
+        specs = resolver.resolve.values.flatten.map(&:to_s).sort
+        specs.should == ['AFAmazonS3Client (1.0.1)', 'AFNetworking (1.3.4)',
+                         'AFOAuth2Client (0.1.2)', 'CargoBay (1.0.0)']
+      end
+      it 'uses a Podfile requirement even when a previously declared ' \
+        'dependency has a different requirement' do
+          @podfile = Podfile.new do
+            platform :ios, '7.0'
+            pod 'InstagramKit' # latest version (3.5.0) requires 'AFNetworking', '~> 2.0'
+            pod 'AFNetworking', '2.0.1'
+          end
+          resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
+          specs = resolver.resolve.values.flatten.map(&:root).map(&:to_s).uniq.sort
+          specs.should == ['AFNetworking (2.0.1)', 'InstagramKit (3.5.0)']
+        end
      it 'holds the context state, such as cached specification sets' do
        @resolver.resolve
        cached_sets = @resolver.send(:cached_sets)
@@ -107,7 +170,7 @@ module Pod
          @resolver.resolve
        end.message
        message.should.match /Unable to find a specification/
-        message.should.match /`Windows` depended upon by BlocksKit/
+        message.should.match /`Windows` depended upon by `BlocksKit`/
      end
      it 'does not raise if all dependencies are supported by the platform of the target definition' do
@@ -119,7 +182,7 @@ module Pod
          platform :ios, '7.0'
          pod 'RestKit', '0.10.3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        resolver.resolve.values.flatten.map(&:name).sort.should == %w(
          FileMD5Hash
          ISO8601DateFormatter
@@ -142,6 +205,24 @@ module Pod
        )
      end
+      it 'handles pre-release dependencies with subspecs' do
+        @podfile = Podfile.new do
+          platform :ios, '7.0'
+          pod 'RestKit', '0.20.0-rc1'
+        end
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
+        resolver.resolve.values.flatten.map(&:to_s).sort.should == [
+          'AFNetworking (1.1.0)',
+          'RestKit (0.20.0-rc1)',
+          'RestKit/Core (0.20.0-rc1)',
+          'RestKit/CoreData (0.20.0-rc1)',
+          'RestKit/Network (0.20.0-rc1)',
+          'RestKit/ObjectMapping (0.20.0-rc1)',
+          'RestKit/Support (0.20.0-rc1)',
+          'SOCKit (1.1)',
+        ]
+      end
      it 'handles correctly subspecs from external sources' do
        @podfile = Podfile.new do
          platform :ios
@@ -158,7 +239,7 @@ module Pod
          end
        end
        config.sandbox.expects(:specification).with('MainSpec').returns(spec)
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:name).sort
        specs.should == %w(
          MainSpec/FirstSubSpec MainSpec/FirstSubSpec/SecondSubSpec
@@ -171,7 +252,7 @@ module Pod
          pod 'FileMD5Hash'
          pod 'JSONKit', :head
        end
-        resolver = Resolver.new(config.sandbox, podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
        filemd5hash, jsonkit = resolver.resolve.values.first.sort_by(&:name)
        filemd5hash.version.should.not.be.head
        jsonkit.version.should.be.head
@@ -179,15 +260,41 @@ module Pod
        config.sandbox.head_pod?('JSONKit').should.be.true
      end
-      it 'raises if it finds two conflicting dependencies' do
+      it 'raises if it finds two conflicting explicit dependencies' do
        podfile = Podfile.new do
          platform :ios
          pod 'JSONKit', '1.4'
          pod 'JSONKit', '1.5pre'
        end
-        resolver = Resolver.new(config.sandbox, podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
-        e = lambda { resolver.resolve }.should.raise Pod::Informative
+        e = lambda { resolver.resolve }.should.raise Informative
+        e.message.should.match(/Unable to satisfy the following requirements/)
+        e.message.should.match(/`JSONKit \(= 1.4\)` required by `Podfile`/)
+        e.message.should.match(/`JSONKit \(= 1.5pre\)` required by `Podfile`/)
+      end
+      it 'raises if it finds two conflicting dependencies' do
+        podfile = Podfile.new do
+          platform :ios
+          pod 'RestKit', '0.23.3' # dependends on AFNetworking ~> 1.3.0
+          pod 'AFNetworking', '> 2'
+        end
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
+        e = lambda { resolver.resolve }.should.raise Informative
        e.message.should.match(/Unable to satisfy the following requirements/)
+        e.message.should.match(/`AFNetworking \(~> 1.3.0\)` required by `RestKit\/Network \(.*\)`/)
+        e.message.should.match(/`AFNetworking \(> 2\)` required by `Podfile`/)
+      end
+      it 'raises if no such version of a dependency exists' do
+        podfile = Podfile.new do
+          platform :ios
+          pod 'AFNetworking', '3.0.1'
+        end
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
+        e = lambda { resolver.resolve }.should.raise Informative
+        e.message.should.match(/Unable to satisfy the following requirements/)
+        e.message.should.match(/`AFNetworking \(= 3.0.1\)` required by `Podfile`/)
      end
      it 'takes into account locked dependencies' do
@@ -195,45 +302,16 @@ module Pod
          platform :ios
          pod 'JSONKit', '<= 1.5pre'
        end
-        resolver = Resolver.new(config.sandbox, podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, SourcesManager.all)
        version = resolver.resolve.values.flatten.first.version
        version.to_s.should == '1.5pre'
-        locked_deps = [Dependency.new('JSONKit', '= 1.4')]
+        locked_deps = dependency_graph_from_array([Dependency.new('JSONKit', '= 1.4')])
        resolver = Resolver.new(config.sandbox, podfile, locked_deps, SourcesManager.all)
        version = resolver.resolve.values.flatten.first.version
        version.to_s.should == '1.4'
      end
-      xit 'takes into account locked implicit dependencies' do
-        podfile = Podfile.new do
-          platform :ios, '8.0'
-          pod 'ARAnalytics/Mixpanel'
-        end
-        lockfile_yaml = <<-EOS
-PODS:
-  - ARAnalytics/CoreIOS (2.8.0)
-  - ARAnalytics/Mixpanel (2.8.0):
-    - ARAnalytics/CoreIOS
-    - Mixpanel
-  - Mixpanel (2.5.1)
-DEPENDENCIES:
-  - ARAnalytics/Mixpanel
-SPEC CHECKSUMS:
-  ARAnalytics: 93c5b65989145f88f4d45e262612eac277b0c219
-  Mixpanel: 0115466ba70fd12e67ac4d3d071408dd1d489657
-COCOAPODS: 0.33.1
-        EOS
-        lockfile = Lockfile.new(YAMLHelper.load_string(lockfile_yaml))
-        resolver = Resolver.new(config.sandbox, podfile, lockfile.dependencies, SourcesManager.all)
-        resolver.resolve.values.first.
-          find { |s| s.name == 'Mixpanel' }.
-          version.to_s.should == '2.5.1'
-      end
      it 'consults all sources when finding a matching spec' do
        podfile = Podfile.new do
          platform :ios
@@ -241,13 +319,13 @@ COCOAPODS: 0.33.1
        end
        file = fixture('spec-repos/test_repo/JSONKit/999.999.999/JSONKit.podspec')
        sources = SourcesManager.sources(%w(master test_repo))
-        resolver = Resolver.new(config.sandbox, podfile, [], sources)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources)
        spec = resolver.resolve.values.flatten.first
        spec.version.to_s.should == '999.999.999'
        spec.defined_in_file.should == file
        sources = SourcesManager.sources(%w(test_repo master))
-        resolver = Resolver.new(config.sandbox, podfile, [], sources)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources)
        spec = resolver.resolve.values.flatten.first
        spec.version.to_s.should == '999.999.999'
        resolver.resolve.values.flatten.first.defined_in_file.should == file
@@ -260,13 +338,13 @@ COCOAPODS: 0.33.1
          pod 'JSONKit', '1.4'
        end
        sources = SourcesManager.sources(%w(master test_repo))
-        resolver = Resolver.new(config.sandbox, podfile, [], sources)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources)
        spec = resolver.resolve.values.flatten.first
        spec.version.to_s.should == '1.4'
        spec.defined_in_file.should == fixture('spec-repos/master/Specs/JSONKit/1.4/JSONKit.podspec.json')
        sources = SourcesManager.sources(%w(test_repo master))
-        resolver = Resolver.new(config.sandbox, podfile, [], sources)
+        resolver = Resolver.new(config.sandbox, podfile, empty_graph, sources)
        spec = resolver.resolve.values.flatten.first
        spec.version.to_s.should == '1.4'
        resolver.resolve.values.flatten.first.defined_in_file.should == fixture('spec-repos/test_repo/JSONKit/1.4/JSONKit.podspec')
@@ -285,90 +363,90 @@ COCOAPODS: 0.33.1
          pod 'AFNetworking', '1.0RC3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should == ['AFNetworking (1.0RC3)']
      end
-      xit 'resolves to latest minor version even when explicitly requesting pre-release versions when using ~>' do
+      it 'resolves to latest minor version even when explicitly requesting pre-release versions when using ~>' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '~> 1.0RC3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
-        specs.should == ['AFNetworking (1.2.0)']
+        specs.should == ['AFNetworking (1.3.4)']
      end
-      xit 'does not resolve to a pre-release version implicitly when matching exact version' do
+      it 'does not resolve to a pre-release version implicitly when matching exact version' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '1.0'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (1.0)']
      end
-      xit 'does not resolve to a pre-release version implicitly when using <' do
+      it 'does not resolve to a pre-release version implicitly when using <' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '< 1.0'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (0.10.1)']
      end
-      xit 'does not resolve to a pre-release version implicitly when using <=' do
+      it 'does not resolve to a pre-release version implicitly when using <=' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '<= 1.0'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (1.0)']
      end
-      xit 'does not resolve to a pre-release version implicitly when using >' do
+      it 'does not resolve to a pre-release version implicitly when using >' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '> 1.0', '< 1.3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (1.2.1)']
      end
-      xit 'does not resolve to a pre-release version implicitly when using >=' do
+      it 'does not resolve to a pre-release version implicitly when using >=' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '>= 1.0', '< 1.3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (1.2.1)']
      end
-      xit 'does not resolve to a pre-release version implicitly when using ~>' do
+      it 'does not resolve to a pre-release version implicitly when using ~>' do
        @podfile = Podfile.new do
          platform :ios, '6.0'
          pod 'AFNetworking', '~> 1.0', '< 1.3'
        end
-        resolver = Resolver.new(config.sandbox, @podfile, [], SourcesManager.all)
+        resolver = Resolver.new(config.sandbox, @podfile, empty_graph, SourcesManager.all)
        specs = resolver.resolve.values.flatten.map(&:to_s).sort
        specs.should != ['AFNetworking (1.0RC3)']
        specs.should == ['AFNetworking (1.2.1)']