1 files changed, 8 insertions, 1 deletions
diff --git a/lib/bundler/resolver/spec_group.rb b/lib/bundler/resolver/spec_group.rb
index 1e2a9f5929..70c6de9e0c 100644
--- a/lib/bundler/resolver/spec_group.rb
+++ b/lib/bundler/resolver/spec_group.rb
@@ -5,7 +5,6 @@ module Bundler
     class SpecGroup
       include GemHelpers
 
-      attr_reader :all_specs
       attr_accessor :name, :version, :source
       attr_accessor :ignores_bundler_dependencies
 
@@ -39,6 +38,14 @@ module Bundler
         @activated_platforms << platform
       end
 
+      def copy_for(platform)
+        copied_sg = self.class.new(@all_specs)
+        copied_sg.ignores_bundler_dependencies = @ignores_bundler_dependencies
+        return nil unless copied_sg.for?(platform)
+        copied_sg.activate_platform!(platform)
+        copied_sg
+      end
+
       def spec(platform)
         @specs[platform]
       end