Now won't wait for dependencies that will never install. Partial fix for #3692

lib/bundler/installer/parallel_installer.rb

@@ -35,13 +35,14 @@ def ignorable_dependency?(dep)
     # sure needed dependencies have been installed.
     def dependencies_installed?(all_specs)
       installed_specs = all_specs.select(&:installed?).map(&:name)
-      dependencies.all? {|d| installed_specs.include? d.name }
+      dependencies(all_specs.map(&:name)).all? {|d| installed_specs.include? d.name }
     end
 
-    # Represents only the non-development dependencies and the ones that
-    # are itself.
-    def dependencies
-      @dependencies ||= all_dependencies.reject {|dep| ignorable_dependency? dep }
+    # Represents only the non-development dependencies, the ones that are
+    # itself and are in the total list.
+    def dependencies(all_spec_names)
+      @dependencies ||= all_dependencies.reject {|dep| ignorable_dependency? dep }.
+                                         select {|dep| all_spec_names.include? dep.name }
     end
 
     # Represents all dependencies

spec/install/parallel/spec_installation_spec.rb

@@ -57,5 +57,18 @@ def a_spec.name
         expect(spec.dependencies_installed?(all_specs)).to be_falsey
       end
     end
+
+    context "when dependencies that are not on the overall installation list are the only ones not installed" do
+      it "returns true" do
+        dependencies = []
+        dependencies << instance_double("SpecInstallation", :spec => "alpha", :name => "alpha", :installed? => true, :all_dependencies => [], :type => :production)
+        all_specs = dependencies + [instance_double("SpecInstallation", :spec => "gamma", :name => "gamma", :installed? => false, :all_dependencies => [], :type => :production)]
+        # Add dependency which is not in all_specs
+        dependencies << instance_double("SpecInstallation", :spec => "beta", :name => "beta", :installed? => false, :all_dependencies => [], :type => :production)
+        spec = ParallelInstaller::SpecInstallation.new(dep)
+        allow(spec).to receive(:all_dependencies).and_return(dependencies)
+        expect(spec.dependencies_installed?(all_specs)).to be_truthy
+      end
+    end
   end
 end