diff --git a/lib/bundler/dep_proxy.rb b/lib/bundler/dep_proxy.rb
index 47de2968108..f007546777a 100644
--- a/lib/bundler/dep_proxy.rb
+++ b/lib/bundler/dep_proxy.rb
@@ -29,13 +29,16 @@ def requirement
     end
 
     def to_s
-      "#{name} (#{requirement}) #{__platform}"
+      s = name.dup
+      s << " (#{requirement})" unless requirement == Gem::Requirement.default
+      s << " #{__platform}" unless __platform == Gem::Platform::RUBY
+      s
     end
 
   private
 
-    def method_missing(*args)
-      @dep.send(*args)
+    def method_missing(*args, &blk)
+      @dep.send(*args, &blk)
     end
   end
 end
diff --git a/lib/bundler/resolver.rb b/lib/bundler/resolver.rb
index 14a33f5e463..ff05e78c9d2 100644
--- a/lib/bundler/resolver.rb
+++ b/lib/bundler/resolver.rb
@@ -1,51 +1,40 @@
-require "set"
-
-# This is the latest iteration of the gem dependency resolving algorithm. As of now,
-# it can resolve (as a success or failure) any set of gem dependencies we throw at it
-# in a reasonable amount of time. The most iterations I've seen it take is about 150.
-# The actual implementation of the algorithm is not as good as it could be yet, but that
-# can come later.
-
 module Bundler
   class Resolver
     require "bundler/vendored_molinillo"
 
     class Molinillo::VersionConflict
-      def clean_req(req)
-        if req.to_s.include?(">= 0")
-          req.to_s.gsub(/ \(.*?\)$/, "")
-        else
-          req.to_s.gsub(/\, (runtime|development)\)$/, ")")
-        end
-      end
-
       def message
-        conflicts.values.flatten.reduce("") do |o, conflict|
-          o << %(Bundler could not find compatible versions for gem "#{conflict.requirement.name}":\n)
+        conflicts.sort.reduce("") do |o, (name, conflict)|
+          o << %(Bundler could not find compatible versions for gem "#{name}":\n)
           if conflict.locked_requirement
             o << %(  In snapshot (#{Bundler.default_lockfile.basename}):\n)
-            o << %(    #{clean_req conflict.locked_requirement}\n)
+            o << %(    #{DepProxy.new(conflict.locked_requirement, Gem::Platform::RUBY)}\n)
             o << %(\n)
           end
           o << %(  In Gemfile:\n)
-          o << conflict.requirement_trees.map do |tree|
+          o << conflict.requirement_trees.sort_by {|t| t.reverse.map(&:name) }.map do |tree|
             t = ""
             depth = 2
             tree.each do |req|
-              t << "  " * depth << %(#{clean_req req})
-              t << %( depends on) unless tree[-1] == req
+              t << "  " * depth << req.to_s
+              unless tree.last == req
+                if spec = conflict.activated_by_name[req.name]
+                  t << %( was resolved to #{spec.version}, which)
+                end
+                t << %( depends on)
+              end
               t << %(\n)
               depth += 1
             end
             t
           end.join("\n")
 
-          if conflict.requirement.name == "bundler"
+          if name == "bundler"
             o << %(\n  Current Bundler version:\n    bundler (#{Bundler::VERSION}))
             other_bundler_required = !conflict.requirement.requirement.satisfied_by?(Gem::Version.new Bundler::VERSION)
           end
 
-          if conflict.requirement.name == "bundler" && other_bundler_required
+          if name == "bundler" && other_bundler_required
             o << "\n"
             o << "This Gemfile requires a different version of Bundler.\n"
             o << "Perhaps you need to update Bundler by running `gem install bundler`?\n"
@@ -55,11 +44,12 @@ def message
             o << %(Running `bundle update` will rebuild your snapshot from scratch, using only\n)
             o << %(the gems in your Gemfile, which may resolve the conflict.\n)
           elsif !conflict.existing
+            o << "\n"
             if conflict.requirement_trees.first.size > 1
-              o << "Could not find gem '#{clean_req(conflict.requirement)}', which is required by "
-              o << "gem '#{clean_req(conflict.requirement_trees.first[-2])}', in any of the sources."
+              o << "Could not find gem '#{conflict.requirement}', which is required by "
+              o << "gem '#{conflict.requirement_trees.first[-2]}', in any of the sources."
             else
-              o << "Could not find gem '#{clean_req(conflict.requirement)} in any of the sources\n"
+              o << "Could not find gem '#{conflict.requirement}' in any of the sources\n"
             end
           end
           o
@@ -189,7 +179,7 @@ def initialize(index, source_requirements, base)
       @resolver = Molinillo::Resolver.new(self, self)
       @search_for = {}
       @base_dg = Molinillo::DependencyGraph.new
-      @base.each {|ls| @base_dg.add_root_vertex ls.name, Dependency.new(ls.name, ls.version) }
+      @base.each {|ls| @base_dg.add_vertex(ls.name, Dependency.new(ls.name, ls.version), true) }
     end
 
     def start(requirements)
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/dependency_graph.rb b/lib/bundler/vendor/molinillo/lib/molinillo/dependency_graph.rb
index 7cde9fa5ebb..655b0ebb970 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/dependency_graph.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/dependency_graph.rb
@@ -34,40 +34,34 @@ def self.tsort(vertices)
     # A directed edge of a {DependencyGraph}
     # @attr [Vertex] origin The origin of the directed edge
     # @attr [Vertex] destination The destination of the directed edge
-    # @attr [Array] requirements The requirements the directed edge represents
-    Edge = Struct.new(:origin, :destination, :requirements)
+    # @attr [Object] requirement The requirement the directed edge represents
+    Edge = Struct.new(:origin, :destination, :requirement)
 
-    # @return [{String => Vertex}] vertices that have no {Vertex#predecessors},
-    #   keyed by by {Vertex#name}
-    attr_reader :root_vertices
     # @return [{String => Vertex}] the vertices of the dependency graph, keyed
     #   by {Vertex#name}
     attr_reader :vertices
-    # @return [Set<Edge>] the edges of the dependency graph
-    attr_reader :edges
 
     def initialize
       @vertices = {}
-      @edges = Set.new
-      @root_vertices = {}
     end
 
     # Initializes a copy of a {DependencyGraph}, ensuring that all {#vertices}
-    # have the correct {Vertex#graph} set
+    # are properly copied.
     def initialize_copy(other)
       super
-      @vertices = other.vertices.reduce({}) do |vertices, (name, vertex)|
-        vertices.tap do |hash|
-          hash[name] = vertex.dup.tap { |v| v.graph = self }
+      @vertices = {}
+      traverse = lambda do |new_v, old_v|
+        return if new_v.outgoing_edges.size == old_v.outgoing_edges.size
+        old_v.outgoing_edges.each do |edge|
+          destination = add_vertex(edge.destination.name, edge.destination.payload)
+          add_edge_no_circular(new_v, destination, edge.requirement)
+          traverse.call(destination, edge.destination)
         end
       end
-      @root_vertices = Hash[@vertices.select { |n, _v| other.root_vertices[n] }]
-      @edges = other.edges.map do |edge|
-        Edge.new(
-          vertex_named(edge.origin.name),
-          vertex_named(edge.destination.name),
-          edge.requirements.dup
-        )
+      other.vertices.each do |name, vertex|
+        new_vertex = add_vertex(name, vertex.payload, vertex.root?)
+        new_vertex.explicit_requirements.replace(vertex.explicit_requirements)
+        traverse.call(new_vertex, vertex)
       end
     end
 
@@ -80,7 +74,12 @@ def inspect
     #   by a recursive traversal of each {#root_vertices} and its
     #   {Vertex#successors}
     def ==(other)
-      root_vertices == other.root_vertices
+      return false unless other
+      vertices.each do |name, vertex|
+        other_vertex = other.vertex_named(name)
+        return false unless other_vertex
+        return false unless other_vertex.successors.map(&:name).to_set == vertex.successors.map(&:name).to_set
+      end
     end
 
     # @param [String] name
@@ -89,15 +88,13 @@ def ==(other)
     # @param [Object] requirement the requirement that is requiring the child
     # @return [void]
     def add_child_vertex(name, payload, parent_names, requirement)
-      is_root = parent_names.include?(nil)
-      parent_nodes = parent_names.compact.map { |n| vertex_named(n) }
-      vertex = vertex_named(name) || if is_root
-                                       add_root_vertex(name, payload)
-                                     else
-                                       add_vertex(name, payload)
-                                     end
-      vertex.payload ||= payload
-      parent_nodes.each do |parent_node|
+      vertex = add_vertex(name, payload)
+      parent_names.each do |parent_name|
+        unless parent_name
+          vertex.root = true
+          next
+        end
+        parent_node = vertex_named(parent_name)
         add_edge(parent_node, vertex, requirement)
       end
       vertex
@@ -106,16 +103,11 @@ def add_child_vertex(name, payload, parent_names, requirement)
     # @param [String] name
     # @param [Object] payload
     # @return [Vertex] the vertex that was added to `self`
-    def add_vertex(name, payload)
-      vertex = vertices[name] ||= Vertex.new(self, name, payload)
-      vertex.tap { |v| v.payload = payload }
-    end
-
-    # @param [String] name
-    # @param [Object] payload
-    # @return [Vertex] the vertex that was added to `self`
-    def add_root_vertex(name, payload)
-      add_vertex(name, payload).tap { |v| root_vertices[name] = v }
+    def add_vertex(name, payload, root = false)
+      vertex = vertices[name] ||= Vertex.new(name, payload)
+      vertex.payload ||= payload
+      vertex.root ||= root
+      vertex
     end
 
     # Detaches the {#vertex_named} `name` {Vertex} from the graph, recursively
@@ -123,12 +115,12 @@ def add_root_vertex(name, payload)
     # @param [String] name
     # @return [void]
     def detach_vertex_named(name)
-      vertex = vertex_named(name)
-      return unless vertex
-      successors = vertex.successors
-      vertices.delete(name)
-      edges.reject! { |e| e.origin == vertex || e.destination == vertex }
-      successors.each { |v| detach_vertex_named(v.name) unless root_vertices[v.name] || v.predecessors.any? }
+      return unless vertex = vertices.delete(name)
+      vertex.outgoing_edges.each do |e|
+        v = e.destination
+        v.incoming_edges.delete(e)
+        detach_vertex_named(v.name) unless v.root? || v.predecessors.any?
+      end
     end
 
     # @param [String] name
@@ -140,7 +132,8 @@ def vertex_named(name)
     # @param [String] name
     # @return [Vertex,nil] the root vertex with the given name
     def root_vertex_named(name)
-      root_vertices[name]
+      vertex = vertex_named(name)
+      vertex if vertex && vertex.root?
     end
 
     # Adds a new {Edge} to the dependency graph
@@ -149,18 +142,24 @@ def root_vertex_named(name)
     # @param [Object] requirement the requirement that this edge represents
     # @return [Edge] the added edge
     def add_edge(origin, destination, requirement)
-      if origin == destination || destination.path_to?(origin)
+      if destination.path_to?(origin)
         raise CircularDependencyError.new([origin, destination])
       end
-      Edge.new(origin, destination, [requirement]).tap { |e| edges << e }
+      add_edge_no_circular(origin, destination, requirement)
+    end
+
+    private
+
+    def add_edge_no_circular(origin, destination, requirement)
+      edge = Edge.new(origin, destination, requirement)
+      origin.outgoing_edges << edge
+      destination.incoming_edges << edge
+      edge
     end
 
     # A vertex in a {DependencyGraph} that encapsulates a {#name} and a
     # {#payload}
     class Vertex
-      # @return [DependencyGraph] the graph this vertex is a node of
-      attr_accessor :graph
-
       # @return [String] the name of the vertex
       attr_accessor :name
 
@@ -171,50 +170,62 @@ class Vertex
       #   this vertex
       attr_reader :explicit_requirements
 
-      # @param [DependencyGraph] graph see {#graph}
+      # @return [Boolean] whether the vertex is considered a root vertex
+      attr_accessor :root
+      alias_method :root?, :root
+
       # @param [String] name see {#name}
       # @param [Object] payload see {#payload}
-      def initialize(graph, name, payload)
-        @graph = graph
+      def initialize(name, payload)
         @name = name
         @payload = payload
         @explicit_requirements = []
+        @outgoing_edges = []
+        @incoming_edges = []
       end
 
       # @return [Array<Object>] all of the requirements that required
       #   this vertex
       def requirements
-        incoming_edges.map(&:requirements).flatten + explicit_requirements
+        incoming_edges.map(&:requirement) + explicit_requirements
       end
 
       # @return [Array<Edge>] the edges of {#graph} that have `self` as their
       #   {Edge#origin}
-      def outgoing_edges
-        graph.edges.select { |e| e.origin.shallow_eql?(self) }
-      end
+      attr_accessor :outgoing_edges
 
       # @return [Array<Edge>] the edges of {#graph} that have `self` as their
       #   {Edge#destination}
-      def incoming_edges
-        graph.edges.select { |e| e.destination.shallow_eql?(self) }
-      end
+      attr_accessor :incoming_edges
 
-      # @return [Set<Vertex>] the vertices of {#graph} that have an edge with
+      # @return [Array<Vertex>] the vertices of {#graph} that have an edge with
       #   `self` as their {Edge#destination}
       def predecessors
-        incoming_edges.map(&:origin).to_set
+        incoming_edges.map(&:origin)
+      end
+
+      # @return [Array<Vertex>] the vertices of {#graph} where `self` is a
+      #   {#descendent?}
+      def recursive_predecessors
+        vertices = predecessors
+        vertices += vertices.map(&:recursive_predecessors).flatten(1)
+        vertices.uniq!
+        vertices
       end
 
-      # @return [Set<Vertex>] the vertices of {#graph} that have an edge with
+      # @return [Array<Vertex>] the vertices of {#graph} that have an edge with
       #   `self` as their {Edge#origin}
       def successors
-        outgoing_edges.map(&:destination).to_set
+        outgoing_edges.map(&:destination)
       end
 
-      # @return [Set<Vertex>] the vertices of {#graph} where `self` is an
+      # @return [Array<Vertex>] the vertices of {#graph} where `self` is an
       #   {#ancestor?}
       def recursive_successors
-        successors + successors.map(&:recursive_successors).reduce(Set.new, &:+)
+        vertices = successors
+        vertices += vertices.map(&:recursive_successors).flatten(1)
+        vertices.uniq!
+        vertices
       end
 
       # @return [String] a string suitable for debugging
@@ -226,7 +237,7 @@ def inspect
       #   by a recursive traversal of each {Vertex#successors}
       def ==(other)
         shallow_eql?(other) &&
-          successors == other.successors
+          successors.to_set == other.successors.to_set
       end
 
       # @return [Boolean] whether the two vertices are equal, determined
@@ -248,7 +259,7 @@ def hash
       # dependency graph?
       # @return true iff there is a path following edges within this {#graph}
       def path_to?(other)
-        successors.include?(other) || successors.any? { |v| v.path_to?(other) }
+        equal?(other) || successors.any? { |v| v.path_to?(other) }
       end
 
       alias_method :descendent?, :path_to?
@@ -257,7 +268,7 @@ def path_to?(other)
       # dependency graph?
       # @return true iff there is a path following edges within this {#graph}
       def ancestor?(other)
-        predecessors.include?(other) || predecessors.any? { |v| v.ancestor?(other) }
+        other.path_to?(self)
       end
 
       alias_method :is_reachable_from?, :ancestor?
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb b/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
index 0e8e4372405..a58ee533148 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/gem_metadata.rb
@@ -1,3 +1,3 @@
 module Bundler::Molinillo
-  VERSION = '0.3.0'
+  VERSION = '0.4.0'
 end
diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb b/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
index fc7fe86c7d3..51cfa101b1e 100644
--- a/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/resolution.rb
@@ -12,13 +12,15 @@ class Resolution
       # @attr [Object] locked_requirement the relevant locking requirement.
       # @attr [Array<Array<Object>>] requirement_trees the different requirement
       #   trees that led to every requirement for the conflicting name.
+      # @attr [{String=>Object}] activated_by_name the already-activated specs.
       Conflict = Struct.new(
         :requirement,
         :requirements,
         :existing,
         :possibility,
         :locked_requirement,
-        :requirement_trees
+        :requirement_trees,
+        :activated_by_name
       )
 
       # @return [SpecificationProvider] the provider that knows about
@@ -164,7 +166,7 @@ def state
       # @return [DependencyState] the initial state for the resolution
       def initial_state
         graph = DependencyGraph.new.tap do |dg|
-          original_requested.each { |r| dg.add_root_vertex(name_for(r), nil).tap { |v| v.explicit_requirements << r } }
+          original_requested.each { |r| dg.add_vertex(name_for(r), nil, true).tap { |v| v.explicit_requirements << r } }
         end
 
         requirements = sort_dependencies(original_requested, graph, {})
@@ -216,7 +218,7 @@ def parent_of(requirement)
         return nil unless requirement
         seen = false
         state = states.reverse_each.find do |s|
-          seen ||= s.requirement == requirement
+          seen ||= s.requirement == requirement || s.requirements.include?(requirement)
           seen && s.requirement != requirement && !s.requirements.include?(requirement)
         end
         state && state.requirement
@@ -250,21 +252,23 @@ def create_conflict
           name_for_explicit_dependency_source => vertex.explicit_requirements,
           name_for_locking_dependency_source => Array(locked_requirement_named(name)),
         }
-        vertex.incoming_edges.each { |edge| (requirements[edge.origin.payload] ||= []).unshift(*edge.requirements) }
+        vertex.incoming_edges.each { |edge| (requirements[edge.origin.payload] ||= []).unshift(edge.requirement) }
         conflicts[name] = Conflict.new(
           requirement,
           Hash[requirements.select { |_, r| !r.empty? }],
           vertex.payload,
           possibility,
           locked_requirement_named(name),
-          requirement_trees
+          requirement_trees,
+          Hash[activated.map { |v| [v.name, v.payload] }.select(&:last)]
         )
       end
 
       # @return [Array<Array<Object>>] The different requirement
       #   trees that led to every requirement for the current spec.
       def requirement_trees
-        activated.vertex_named(name).requirements.map { |r| requirement_tree_for(r) }
+        vertex = activated.vertex_named(name)
+        vertex.requirements.map { |r| requirement_tree_for(r) }
       end
 
       # @return [Array<Object>] the list of requirements that led to
@@ -322,7 +326,7 @@ def attempt_to_activate_existing_spec(existing_node)
         existing_spec = existing_node.payload
         if requirement_satisfied_by?(requirement, activated, existing_spec)
           new_requirements = requirements.dup
-          push_state_for_requirements(new_requirements)
+          push_state_for_requirements(new_requirements, false)
         else
           return if attempt_to_swap_possibility
           create_conflict
@@ -389,17 +393,17 @@ def activate_spec
       def require_nested_dependencies_for(activated_spec)
         nested_dependencies = dependencies_for(activated_spec)
         debug(depth) { "Requiring nested dependencies (#{nested_dependencies.map(&:to_s).join(', ')})" }
-        nested_dependencies.each { |d|  activated.add_child_vertex name_for(d), nil, [name_for(activated_spec)], d }
+        nested_dependencies.each { |d| activated.add_child_vertex(name_for(d), nil, [name_for(activated_spec)], d) }
 
-        push_state_for_requirements(requirements + nested_dependencies)
+        push_state_for_requirements(requirements + nested_dependencies, nested_dependencies.size > 0)
       end
 
       # Pushes a new {DependencyState} that encapsulates both existing and new
       # requirements
       # @param [Array] new_requirements
       # @return [void]
-      def push_state_for_requirements(new_requirements, new_activated = activated.dup)
-        new_requirements = sort_dependencies(new_requirements.uniq, new_activated, conflicts)
+      def push_state_for_requirements(new_requirements, requires_sort = true, new_activated = activated.dup)
+        new_requirements = sort_dependencies(new_requirements.uniq, new_activated, conflicts) if requires_sort
         new_requirement = new_requirements.shift
         new_name = new_requirement ? name_for(new_requirement) : ''
         possibilities = new_requirement ? search_for(new_requirement) : []
@@ -420,7 +424,7 @@ def push_state_for_requirements(new_requirements, new_activated = activated.dup)
       def handle_missing_or_push_dependency_state(state)
         if state.requirement && state.possibilities.empty? && allow_missing?(state.requirement)
           state.activated.detach_vertex_named(state.name)
-          push_state_for_requirements(state.requirements, state.activated)
+          push_state_for_requirements(state.requirements.dup, false, state.activated)
         else
           states.push state
         end
diff --git a/spec/commands/install_spec.rb b/spec/commands/install_spec.rb
index 2e1a206f21d..f6648ac6b00 100644
--- a/spec/commands/install_spec.rb
+++ b/spec/commands/install_spec.rb
@@ -370,7 +370,7 @@
       G
 
       bundle :install, :quiet => true
-      expect(out).to include("Could not find gem 'rack (>= 0) ruby'")
+      expect(out).to include("Could not find gem 'rack'")
       expect(out).to_not include("Your Gemfile has no gem server sources")
     end
   end
diff --git a/spec/install/bundler_spec.rb b/spec/install/bundler_spec.rb
index 930d7095fc9..4bbfb135c12 100644
--- a/spec/install/bundler_spec.rb
+++ b/spec/install/bundler_spec.rb
@@ -41,7 +41,7 @@
         Resolving dependencies...
         Bundler could not find compatible versions for gem "bundler":
           In Gemfile:
-            bundler (= 0.9.2) ruby
+            bundler (= 0.9.2)
 
           Current Bundler version:
             bundler (#{Bundler::VERSION})
@@ -98,11 +98,11 @@
         Resolving dependencies...
         Bundler could not find compatible versions for gem "activesupport":
           In Gemfile:
-            activemerchant (>= 0) ruby depends on
-              activesupport (>= 2.0.0) ruby
+            activemerchant was resolved to 1.0, which depends on
+              activesupport (>= 2.0.0)
 
-            rails_fail (>= 0) ruby depends on
-              activesupport (= 1.2.3) ruby
+            rails_fail was resolved to 1.0, which depends on
+              activesupport (= 1.2.3)
       E
       expect(out).to eq(nice_error)
     end
@@ -119,10 +119,10 @@
         Resolving dependencies...
         Bundler could not find compatible versions for gem "activesupport":
           In Gemfile:
-            rails_fail (>= 0) ruby depends on
-              activesupport (= 1.2.3) ruby
+            activesupport (= 2.3.5)
 
-            activesupport (= 2.3.5) ruby
+            rails_fail was resolved to 1.0, which depends on
+              activesupport (= 1.2.3)
       E
       expect(out).to eq(nice_error)
     end
diff --git a/spec/install/gems/flex_spec.rb b/spec/install/gems/flex_spec.rb
index d6ff15bf086..8b344cd8ad8 100644
--- a/spec/install/gems/flex_spec.rb
+++ b/spec/install/gems/flex_spec.rb
@@ -200,11 +200,11 @@
             rack (= 0.9.1)
 
           In Gemfile:
-            rack_middleware (>= 0) ruby depends on
-              rack (= 0.9.1) ruby
+            rack-obama (= 2.0) was resolved to 2.0, which depends on
+              rack (= 1.2)
 
-            rack-obama (= 2.0) ruby depends on
-              rack (= 1.2) ruby
+            rack_middleware was resolved to 1.0, which depends on
+              rack (= 0.9.1)
 
         Running `bundle update` will rebuild your snapshot from scratch, using only
         the gems in your Gemfile, which may resolve the conflict.
@@ -277,43 +277,42 @@
     end
   end
 
-  # This was written to test github issue #636, but it passed.
-  # It's insanoly slow (3.36s) so I'm not going to run it
-  # describe "when a locked child dependency conflicts" do
-  #   before(:each) do
-  #     build_repo2 do
-  #       build_gem "capybara", "0.3.9" do |s|
-  #         s.add_dependency "rack", ">= 1.0.0"
-  #       end
-  #
-  #       build_gem "rack", "1.1.0"
-  #       build_gem "rails", "3.0.0.rc4" do |s|
-  #         s.add_dependency "rack", "~> 1.1.0"
-  #       end
-  #
-  #       build_gem "rack", "1.2.1"
-  #       build_gem "rails", "3.0.0" do |s|
-  #         s.add_dependency "rack", "~> 1.2.1"
-  #       end
-  #     end
-  #   end
-  #
-  #   it "prints the correct error message" do
-  #     # install Rails 3.0.0.rc
-  #     install_gemfile <<-G
-  #       source "file://#{gem_repo2}"
-  #       gem "rails", "3.0.0.rc4"
-  #       gem "capybara", "0.3.9"
-  #     G
-  #
-  #     # upgrade Rails to 3.0.0 and then install again
-  #     install_gemfile <<-G
-  #       source "file://#{gem_repo2}"
-  #       gem "rails", "3.0.0"
-  #       gem "capybara", "0.3.9"
-  #     G
-  #
-  #     out.should match(/Gemfile.lock/)
-  #   end
-  # end
+  # This was written to test github issue #636
+  describe "when a locked child dependency conflicts" do
+    before(:each) do
+      build_repo2 do
+        build_gem "capybara", "0.3.9" do |s|
+          s.add_dependency "rack", ">= 1.0.0"
+        end
+
+        build_gem "rack", "1.1.0"
+        build_gem "rails", "3.0.0.rc4" do |s|
+          s.add_dependency "rack", "~> 1.1.0"
+        end
+
+        build_gem "rack", "1.2.1"
+        build_gem "rails", "3.0.0" do |s|
+          s.add_dependency "rack", "~> 1.2.1"
+        end
+      end
+    end
+
+    it "prints the correct error message" do
+      # install Rails 3.0.0.rc
+      install_gemfile <<-G
+        source "file://#{gem_repo2}"
+        gem "rails", "3.0.0.rc4"
+        gem "capybara", "0.3.9"
+      G
+
+      # upgrade Rails to 3.0.0 and then install again
+      install_gemfile <<-G
+        source "file://#{gem_repo2}"
+        gem "rails", "3.0.0"
+        gem "capybara", "0.3.9"
+      G
+
+      expect(out).to include("Gemfile.lock")
+    end
+  end
 end
diff --git a/spec/install/gems/resolving_spec.rb b/spec/install/gems/resolving_spec.rb
index 7ef2535e571..5377db233ed 100644
--- a/spec/install/gems/resolving_spec.rb
+++ b/spec/install/gems/resolving_spec.rb
@@ -96,7 +96,8 @@
             bundle :install, :env => { "DEBUG_RESOLVER_TREE" => "1" }
           end
 
-          expect(resolve_output).to include(" net_b (>= 0) ruby")
+          expect(resolve_output).to include(" net_b")
+          expect(resolve_output).to include(" net_build_extensions (1.0)")
         end
       end
     end
diff --git a/spec/install/gems/sources_spec.rb b/spec/install/gems/sources_spec.rb
index bf302d8d9ec..0206dc1dbf4 100644
--- a/spec/install/gems/sources_spec.rb
+++ b/spec/install/gems/sources_spec.rb
@@ -280,7 +280,7 @@
 
       it "does not install the gem" do
         bundle :install
-        expect(out).to include("Could not find gem 'not_in_repo1 (>= 0) ruby'")
+        expect(out).to include("Could not find gem 'not_in_repo1'")
       end
     end
 
diff --git a/spec/install/post_bundle_message_spec.rb b/spec/install/post_bundle_message_spec.rb
index 1c7847ce50c..39076461dbd 100644
--- a/spec/install/post_bundle_message_spec.rb
+++ b/spec/install/post_bundle_message_spec.rb
@@ -89,7 +89,7 @@
           gem "rack"
           gem "not-a-gem", :group => :development
         G
-        expect(out).to include("Could not find gem 'not-a-gem (>= 0) ruby' in any of the gem sources listed in your Gemfile or available on this machine.")
+        expect(out).to include("Could not find gem 'not-a-gem' in any of the gem sources listed in your Gemfile or available on this machine.")
       end
     end
   end
diff --git a/spec/runtime/inline_spec.rb b/spec/runtime/inline_spec.rb
index 2e33cf9c9f5..a5142d34ed4 100644
--- a/spec/runtime/inline_spec.rb
+++ b/spec/runtime/inline_spec.rb
@@ -69,7 +69,7 @@ def script(code, options = {})
       puts "success"
     RUBY
 
-    expect(err).to include "Could not find gem 'eleven (>= 0) ruby'"
+    expect(err).to include "Could not find gem 'eleven'"
     expect(out).not_to include "success"
 
     script <<-RUBY