[rubygems/rubygems] Preserve the previous behavior of raising an error when in frozen mode

https://github.com/rubygems/rubygems/commit/6e35a6edfe

lib/bundler/lazy_specification.rb

@@ -108,7 +108,11 @@ module Bundler
             (spec.required_ruby_version.satisfied_by?(Gem.ruby_version) &&
               spec.required_rubygems_version.satisfied_by?(Gem.rubygems_version))
         end
+        if search.nil? && Bundler.frozen_bundle?
+          search = candidates.last
+        else
           search.dependencies = dependencies if search && search.full_name == full_name && (search.is_a?(RemoteSpecification) || search.is_a?(EndpointSpecification))
+        end
         search
       end
     end

spec/bundler/install/gems/resolving_spec.rb

@@ -241,7 +241,8 @@ RSpec.describe "bundle install with install-time dependencies" do
         expect(the_bundle).to include_gems("rack 1.2")
       end
 
-      it "automatically updates lockfile to use the older version" do
+      context "when there is a lockfile using the newer incompatible version" do
+        before do
           build_repo2 do
             build_gem "parallel_tests", "3.7.0" do |s|
               s.required_ruby_version = ">= #{current_ruby_minor}"
@@ -272,7 +273,9 @@ RSpec.describe "bundle install with install-time dependencies" do
             BUNDLED WITH
                #{Bundler::VERSION}
           L
+        end
 
+        it "automatically updates lockfile to use the older version" do
           bundle "install --verbose", :artifice => "compact_index", :env => { "BUNDLER_SPEC_GEM_REPO" => gem_repo2.to_s }
 
           expect(lockfile).to eq <<~L
@@ -292,6 +295,16 @@ RSpec.describe "bundle install with install-time dependencies" do
           L
         end
 
+        it "gives a meaningful error if we're in frozen mode" do
+          expect do
+            bundle "install --verbose", :artifice => "compact_index", :env => { "BUNDLER_SPEC_GEM_REPO" => gem_repo2.to_s, "BUNDLE_FROZEN" => "true" }, :raise_on_error => false
+          end.not_to change { lockfile }
+
+          expect(err).to include("parallel_tests-3.8.0 requires ruby version >= #{next_ruby_minor}")
+          expect(err).not_to include("That means the author of parallel_tests (3.8.0) has removed it.")
+        end
+      end
+
       it "gives a meaningful error on ruby version mismatches between dependencies" do
         build_repo4 do
           build_gem "requires-old-ruby" do |s|