20 files changed, 343 insertions, 82 deletions
diff --git a/test/date/test_date.rb b/test/date/test_date.rb
index 3f9c893efa..7e37fc94d2 100644
--- a/test/date/test_date.rb
+++ b/test/date/test_date.rb
@@ -135,6 +135,10 @@ class TestDate < Test::Unit::TestCase
     assert_equal(9, h[DateTime.new(1999,5,25)])
 
     h = {}
+    h[Date.new(3171505571716611468830131104691,2,19)] = 0
+    assert_equal(true, h.key?(Date.new(3171505571716611468830131104691,2,19)))
+
+    h = {}
     h[DateTime.new(1999,5,23)] = 0
     h[DateTime.new(1999,5,24)] = 1
     h[DateTime.new(1999,5,25)] = 2
diff --git a/test/date/test_switch_hitter.rb b/test/date/test_switch_hitter.rb
index bdf299e030..cc75782537 100644
--- a/test/date/test_switch_hitter.rb
+++ b/test/date/test_switch_hitter.rb
@@ -97,6 +97,11 @@ class TestSH < Test::Unit::TestCase
 		 [d.year, d.mon, d.mday, d.hour, d.min, d.sec, d.offset])
   end
 
+  def test_ajd
+    assert_equal(Date.civil(2008, 1, 16).ajd, 4908963r/2)
+    assert_equal(Date.civil(-11082381539297990, 2, 19).ajd, -8095679714453739481r/2)
+  end
+
   def test_ordinal
     d = Date.ordinal
     assert_equal([-4712, 1], [d.year, d.yday])
diff --git a/test/prism/lex_test.rb b/test/prism/lex_test.rb
index 2786c45a22..d34c3d9dd3 100644
--- a/test/prism/lex_test.rb
+++ b/test/prism/lex_test.rb
@@ -17,7 +17,7 @@ module Prism
       "spanning_heredoc.txt",
       "spanning_heredoc_newlines.txt",
       # Prism emits a single :on_tstring_content in <<- style heredocs when there
-      # is a line continuation preceeded by escaped backslashes. It should emit two, same
+      # is a line continuation preceded by escaped backslashes. It should emit two, same
       # as if the backslashes are not present.
       "heredocs_with_fake_newlines.txt",
     ]
diff --git a/test/ruby/test_ast.rb b/test/ruby/test_ast.rb
index 72a0d821a0..d22823470b 100644
--- a/test/ruby/test_ast.rb
+++ b/test/ruby/test_ast.rb
@@ -1397,6 +1397,24 @@ dummy
       assert_locations(node.children[-1].locations, [[1, 0, 1, 16], [1, 0, 1, 5], [1, 8, 1, 9], [1, 13, 1, 16]])
     end
 
+    def test_colon2_locations
+      node = ast_parse("A::B")
+      assert_locations(node.children[-1].locations, [[1, 0, 1, 4], [1, 1, 1, 3], [1, 3, 1, 4]])
+
+      node = ast_parse("A::B::C")
+      assert_locations(node.children[-1].locations, [[1, 0, 1, 7], [1, 4, 1, 6], [1, 6, 1, 7]])
+      assert_locations(node.children[-1].children[0].locations, [[1, 0, 1, 4], [1, 1, 1, 3], [1, 3, 1, 4]])
+    end
+
+    def test_colon3_locations
+      node = ast_parse("::A")
+      assert_locations(node.children[-1].locations, [[1, 0, 1, 3], [1, 0, 1, 2], [1, 2, 1, 3]])
+
+      node = ast_parse("::A::B")
+      assert_locations(node.children[-1].locations, [[1, 0, 1, 6], [1, 3, 1, 5], [1, 5, 1, 6]])
+      assert_locations(node.children[-1].children[0].locations, [[1, 0, 1, 3], [1, 0, 1, 2], [1, 2, 1, 3]])
+    end
+
     def test_dot2_locations
       node = ast_parse("1..2")
       assert_locations(node.children[-1].locations, [[1, 0, 1, 4], [1, 1, 1, 3]])
diff --git a/test/ruby/test_backtrace.rb b/test/ruby/test_backtrace.rb
index fca7b62030..01a757f827 100644
--- a/test/ruby/test_backtrace.rb
+++ b/test/ruby/test_backtrace.rb
@@ -454,4 +454,10 @@ class TestBacktrace < Test::Unit::TestCase
     foo::Bar.baz
     end;
   end
+
+  def test_backtrace_internal_frame
+    backtrace = tap { break caller_locations(0) }
+    assert_equal(__FILE__, backtrace[1].path) # not "<internal:kernel>"
+    assert_equal("Kernel#tap", backtrace[1].label)
+  end
 end
diff --git a/test/ruby/test_data.rb b/test/ruby/test_data.rb
index bb38f8ec91..dd698fdcc4 100644
--- a/test/ruby/test_data.rb
+++ b/test/ruby/test_data.rb
@@ -280,4 +280,10 @@ class TestData < Test::Unit::TestCase
     assert_not_same(test, loaded)
     assert_predicate(loaded, :frozen?)
   end
+
+  def test_frozen_subclass
+    test = Class.new(Data.define(:a)).freeze.new(a: 0)
+    assert_kind_of(Data, test)
+    assert_equal([:a], test.members)
+  end
 end
diff --git a/test/ruby/test_encoding.rb b/test/ruby/test_encoding.rb
index ee37199be0..0ab357f53a 100644
--- a/test/ruby/test_encoding.rb
+++ b/test/ruby/test_encoding.rb
@@ -33,7 +33,7 @@ class TestEncoding < Test::Unit::TestCase
     encodings.each do |e|
       assert_raise(TypeError) { e.dup }
       assert_raise(TypeError) { e.clone }
-      assert_equal(e.object_id, Marshal.load(Marshal.dump(e)).object_id)
+      assert_same(e, Marshal.load(Marshal.dump(e)))
     end
   end
 
diff --git a/test/ruby/test_gc.rb b/test/ruby/test_gc.rb
index daa645b349..3516cefedf 100644
--- a/test/ruby/test_gc.rb
+++ b/test/ruby/test_gc.rb
@@ -393,12 +393,10 @@ class TestGc < Test::Unit::TestCase
 
       # Create some objects and place it in a WeakMap
       wmap = ObjectSpace::WeakMap.new
-      ary = Array.new(count)
-      enum = count.times
-      enum.each.with_index do |i|
+      ary = Array.new(count) do |i|
         obj = Object.new
-        ary[i] = obj
         wmap[obj] = nil
+        obj
       end
 
       # Run full GC to collect stats about weak references
@@ -421,7 +419,7 @@ class TestGc < Test::Unit::TestCase
       GC.start
 
       # Sometimes the WeakMap has a few elements, which might be held on by registers.
-      assert_operator(wmap.size, :<=, 2)
+      assert_operator(wmap.size, :<=, count / 1000)
 
       assert_operator(GC.latest_gc_info(:weak_references_count), :<=, before_weak_references_count - count + error_tolerance)
       assert_operator(GC.latest_gc_info(:retained_weak_references_count), :<=, before_retained_weak_references_count - count + error_tolerance)
diff --git a/test/ruby/test_io_buffer.rb b/test/ruby/test_io_buffer.rb
index 55296c1f23..62c4667888 100644
--- a/test/ruby/test_io_buffer.rb
+++ b/test/ruby/test_io_buffer.rb
@@ -121,6 +121,16 @@ class TestIOBuffer < Test::Unit::TestCase
     end
   end
 
+  def test_string_mapped_buffer_frozen
+    string = "Hello World".freeze
+    IO::Buffer.for(string) do |buffer|
+      assert_raise IO::Buffer::AccessError, "Buffer is not writable!" do
+        buffer.set_string("abc")
+      end
+      assert_equal "H".ord, buffer.get_value(:U8, 0)
+    end
+  end
+
   def test_non_string
     not_string = Object.new
 
@@ -683,4 +693,17 @@ class TestIOBuffer < Test::Unit::TestCase
     buf.set_string('a', 0, 0)
     assert_predicate buf, :empty?
   end
+
+  # https://bugs.ruby-lang.org/issues/21210
+  def test_bug_21210
+    omit "compaction is not supported on this platform" unless GC.respond_to?(:compact)
+
+    str = +"hello"
+    buf = IO::Buffer.for(str)
+    assert_predicate buf, :valid?
+
+    GC.verify_compaction_references(expand_heap: true, toward: :empty)
+
+    assert_predicate buf, :valid?
+  end
 end
diff --git a/test/ruby/test_object_id.rb b/test/ruby/test_object_id.rb
index 44421ea256..9c0099517b 100644
--- a/test/ruby/test_object_id.rb
+++ b/test/ruby/test_object_id.rb
@@ -198,3 +198,49 @@ class TestObjectIdTooComplexGeneric < TestObjectId
     end
   end
 end
+
+class TestObjectIdRactor < Test::Unit::TestCase
+  def test_object_id_race_free
+    assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      Warning[:experimental] = false
+      class MyClass
+        attr_reader :a, :b, :c
+        def initialize
+          @a = @b = @c = nil
+        end
+      end
+      N = 10_000
+      objs = Ractor.make_shareable(N.times.map { MyClass.new })
+      results = 4.times.map{
+        Ractor.new(objs) { |objs|
+          vars = []
+          ids = []
+          objs.each do |obj|
+            vars << obj.a << obj.b << obj.c
+            ids << obj.object_id
+          end
+          [vars, ids]
+        }
+      }.map(&:value)
+      assert_equal 1, results.uniq.size
+    end;
+  end
+
+  def test_external_object_id_ractor_move
+    assert_separately([], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      Warning[:experimental] = false
+      class MyClass
+        attr_reader :a, :b, :c
+        def initialize
+          @a = @b = @c = nil
+        end
+      end
+      obj = Ractor.make_shareable(MyClass.new)
+      object_id = obj.object_id
+      obj = Ractor.new { Ractor.receive }.send(obj, move: true).value
+      assert_equal object_id, obj.object_id
+    end;
+  end
+end
diff --git a/test/ruby/test_ractor.rb b/test/ruby/test_ractor.rb
index e463b504d1..3fc891da23 100644
--- a/test/ruby/test_ractor.rb
+++ b/test/ruby/test_ractor.rb
@@ -123,7 +123,7 @@ class TestRactor < Test::Unit::TestCase
       require "tempfile"
       require "pathname"
       f = Tempfile.new(["file_to_require_from_ractor", ".rb"])
-      f.write("puts 'success'")
+      f.write("")
       f.flush
       result = Ractor.new(f.path) do |path|
         require Pathname.new(path)
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index 3f79c2afd7..54ad953ee9 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -787,6 +787,12 @@ class TestRubyOptions < Test::Unit::TestCase
     unless /mswin|mingw/ =~ RUBY_PLATFORM
       opts[:rlimit_core] = 0
     end
+    opts[:failed] = proc do |status, message = "", out = ""|
+      if (sig = status.termsig) && Signal.list["SEGV"] == sig
+        out = ""
+      end
+      Test::Unit::CoreAssertions::FailDesc[status, message]
+    end
     ExecOptions = opts.freeze
 
     # The regexp list that should match the entire stderr output.
@@ -847,7 +853,11 @@ class TestRubyOptions < Test::Unit::TestCase
     args.unshift(env)
 
     test_stdin = ""
-    tests = [//, list] unless block
+    if !block
+      tests = [//, list, message]
+    elsif message
+      tests = [[], [], message]
+    end
 
     assert_in_out_err(args, test_stdin, *tests, encoding: "ASCII-8BIT",
                       **SEGVTest::ExecOptions, **opt, &block)
@@ -860,13 +870,12 @@ class TestRubyOptions < Test::Unit::TestCase
   def test_segv_loaded_features
     bug7402 = '[ruby-core:49573]'
 
-    status = assert_segv(['-e', "END {#{SEGVTest::KILL_SELF}}",
-                          '-e', 'class Bogus; def to_str; exit true; end; end',
-                          '-e', '$".clear',
-                          '-e', '$".unshift Bogus.new',
-                          '-e', '(p $"; abort) unless $".size == 1',
-                         ])
-    assert_not_predicate(status, :success?, "segv but success #{bug7402}")
+    assert_segv(['-e', "END {#{SEGVTest::KILL_SELF}}",
+                 '-e', 'class Bogus; def to_str; exit true; end; end',
+                 '-e', '$".clear',
+                 '-e', '$".unshift Bogus.new',
+                 '-e', '(p $"; abort) unless $".size == 1',
+                ], success: false)
   end
 
   def test_segv_setproctitle
diff --git a/test/ruby/test_struct.rb b/test/ruby/test_struct.rb
index ecd8ed196c..db591c306e 100644
--- a/test/ruby/test_struct.rb
+++ b/test/ruby/test_struct.rb
@@ -550,6 +550,12 @@ module TestStruct
     CODE
   end
 
+  def test_frozen_subclass
+    test = Class.new(@Struct.new(:a)).freeze.new(a: 0)
+    assert_kind_of(@Struct, test)
+    assert_equal([:a], test.members)
+  end
+
   class TopStruct < Test::Unit::TestCase
     include TestStruct
 
diff --git a/test/ruby/test_variable.rb b/test/ruby/test_variable.rb
index 49fec2d40e..984045e05d 100644
--- a/test/ruby/test_variable.rb
+++ b/test/ruby/test_variable.rb
@@ -407,6 +407,20 @@ class TestVariable < Test::Unit::TestCase
     }
   end
 
+  def test_exivar_resize_with_compaction_stress
+    omit "compaction doesn't work well on s390x" if RUBY_PLATFORM =~ /s390x/ # https://github.com/ruby/ruby/pull/5077
+    objs = 10_000.times.map do
+      ExIvar.new
+    end
+    EnvUtil.under_gc_compact_stress do
+      10.times do
+        x = ExIvar.new
+        x.instance_variable_set(:@resize, 1)
+        x
+      end
+    end
+  end
+
   def test_local_variables_with_kwarg
     bug11674 = '[ruby-core:71437] [Bug #11674]'
     v = with_kwargs_11(v1:1,v2:2,v3:3,v4:4,v5:5,v6:6,v7:7,v8:8,v9:9,v10:10,v11:11)
diff --git a/test/ruby/test_zjit.rb b/test/ruby/test_zjit.rb
index 6095b0b734..2b171b02b1 100644
--- a/test/ruby/test_zjit.rb
+++ b/test/ruby/test_zjit.rb
@@ -31,6 +31,20 @@ class TestZJIT < Test::Unit::TestCase
     }
   end
 
+  def test_putstring
+    assert_compiles '""', %q{
+      def test = "#{""}"
+      test
+    }, insns: [:putstring]
+  end
+
+  def test_putchilldedstring
+    assert_compiles '""', %q{
+      def test = ""
+      test
+    }, insns: [:putchilledstring]
+  end
+
   def test_leave_param
     assert_compiles '5', %q{
       def test(n) = n
@@ -281,6 +295,34 @@ class TestZJIT < Test::Unit::TestCase
     }, insns: [:opt_ge], call_threshold: 2
   end
 
+  def test_opt_hash_freeze
+    assert_compiles '{}', <<~RUBY, insns: [:opt_hash_freeze]
+      def test = {}.freeze
+      test
+    RUBY
+  end
+
+  def test_opt_ary_freeze
+    assert_compiles '[]', <<~RUBY, insns: [:opt_ary_freeze]
+      def test = [].freeze
+      test
+    RUBY
+  end
+
+  def test_opt_str_freeze
+    assert_compiles '""', <<~RUBY, insns: [:opt_str_freeze]
+      def test = "".freeze
+      test
+    RUBY
+  end
+
+  def test_opt_str_uminus
+    assert_compiles '""', <<~RUBY, insns: [:opt_str_uminus]
+      def test = -""
+      test
+    RUBY
+  end
+
   def test_new_array_empty
     assert_compiles '[]', %q{
       def test = []
@@ -636,6 +678,27 @@ class TestZJIT < Test::Unit::TestCase
     }
   end
 
+  def test_uncached_getconstant_path
+    assert_compiles RUBY_COPYRIGHT.dump, %q{
+      def test = RUBY_COPYRIGHT
+      test
+    }, call_threshold: 1, insns: [:opt_getconstant_path]
+  end
+
+  def test_getconstant_path_autoload
+    # A constant-referencing expression can run arbitrary code through Kernel#autoload.
+    Dir.mktmpdir('autoload') do |tmpdir|
+      autoload_path = File.join(tmpdir, 'test_getconstant_path_autoload.rb')
+      File.write(autoload_path, 'X = RUBY_COPYRIGHT')
+
+      assert_compiles RUBY_COPYRIGHT.dump, %Q{
+        Object.autoload(:X, #{File.realpath(autoload_path).inspect})
+        def test = X
+        test
+      }, call_threshold: 1, insns: [:opt_getconstant_path]
+    end
+  end
+
   def test_send_backtrace
     backtrace = [
       "-e:2:in 'Object#jit_frame1'",
@@ -652,6 +715,32 @@ class TestZJIT < Test::Unit::TestCase
     }, call_threshold: 2
   end
 
+  def test_putspecialobject_vm_core_and_cbase
+    assert_compiles '10', %q{
+      def test
+        alias bar test
+        10
+      end
+
+      test
+      bar
+    }, insns: [:putspecialobject]
+  end
+
+  def test_putspecialobject_const_base
+    assert_compiles '1', %q{
+      Foo = 1
+
+      def test = Foo
+
+      # First call: populates the constant cache
+      test
+      # Second call: triggers ZJIT compilation with warm cache
+      # RubyVM::ZJIT.assert_compiles will panic if this fails to compile
+      test
+    }, call_threshold: 2
+  end
+
   # tool/ruby_vm/views/*.erb relies on the zjit instructions a) being contiguous and
   # b) being reliably ordered after all the other instructions.
   def test_instruction_order
diff --git a/test/rubygems/helper.rb b/test/rubygems/helper.rb
index d847d3b35e..af78bab724 100644
--- a/test/rubygems/helper.rb
+++ b/test/rubygems/helper.rb
@@ -683,6 +683,14 @@ class Gem::TestCase < Test::Unit::TestCase
     path
   end
 
+  def write_dummy_extconf(gem_name)
+    write_file File.join(@tempdir, "extconf.rb") do |io|
+      io.puts "require 'mkmf'"
+      yield io if block_given?
+      io.puts "create_makefile '#{gem_name}'"
+    end
+  end
+
   ##
   # Load a YAML string, the psych 3 way
 
diff --git a/test/rubygems/test_gem_commands_install_command.rb b/test/rubygems/test_gem_commands_install_command.rb
index 77525aed2c..d05cfef653 100644
--- a/test/rubygems/test_gem_commands_install_command.rb
+++ b/test/rubygems/test_gem_commands_install_command.rb
@@ -647,17 +647,10 @@ ERROR:  Possible alternatives: non_existent_with_hint
     @cmd.options[:args] = %w[a]
 
     use_ui @ui do
-      # Don't use Dir.chdir with a block, it warnings a lot because
-      # of a downstream Dir.chdir with a block
-      old = Dir.getwd
-
-      begin
-        Dir.chdir @tempdir
+      Dir.chdir @tempdir do
         assert_raise Gem::MockGemUi::SystemExitException, @ui.error do
           @cmd.execute
         end
-      ensure
-        Dir.chdir old
       end
     end
 
@@ -684,17 +677,10 @@ ERROR:  Possible alternatives: non_existent_with_hint
     @cmd.options[:args] = %w[a]
 
     use_ui @ui do
-      # Don't use Dir.chdir with a block, it warnings a lot because
-      # of a downstream Dir.chdir with a block
-      old = Dir.getwd
-
-      begin
-        Dir.chdir @tempdir
+      Dir.chdir @tempdir do
         assert_raise Gem::MockGemUi::SystemExitException, @ui.error do
           @cmd.execute
         end
-      ensure
-        Dir.chdir old
       end
     end
 
@@ -720,17 +706,10 @@ ERROR:  Possible alternatives: non_existent_with_hint
     @cmd.options[:args] = %w[a]
 
     use_ui @ui do
-      # Don't use Dir.chdir with a block, it warnings a lot because
-      # of a downstream Dir.chdir with a block
-      old = Dir.getwd
-
-      begin
-        Dir.chdir @tempdir
+      Dir.chdir @tempdir do
         assert_raise Gem::MockGemUi::SystemExitException, @ui.error do
           @cmd.execute
         end
-      ensure
-        Dir.chdir old
       end
     end
 
diff --git a/test/rubygems/test_gem_dependency_installer.rb b/test/rubygems/test_gem_dependency_installer.rb
index 56b84160c4..f84881579a 100644
--- a/test/rubygems/test_gem_dependency_installer.rb
+++ b/test/rubygems/test_gem_dependency_installer.rb
@@ -382,13 +382,9 @@ class TestGemDependencyInstaller < Gem::TestCase
     FileUtils.mv f1_gem, @tempdir
     inst = nil
 
-    pwd = Dir.getwd
-    Dir.chdir @tempdir
-    begin
+    Dir.chdir @tempdir do
       inst = Gem::DependencyInstaller.new
       inst.install "f"
-    ensure
-      Dir.chdir pwd
     end
 
     assert_equal %w[f-1], inst.installed_gems.map(&:full_name)
@@ -523,6 +519,58 @@ class TestGemDependencyInstaller < Gem::TestCase
     assert_equal %w[a-1], inst.installed_gems.map(&:full_name)
   end
 
+  def test_install_local_with_extensions_already_installed
+    pend "needs investigation" if Gem.java_platform?
+    pend "ruby.h is not provided by ruby repo" if ruby_repo?
+
+    @spec = quick_gem "a" do |s|
+      s.extensions << "extconf.rb"
+      s.files += %w[extconf.rb a.c]
+    end
+
+    write_dummy_extconf "a"
+
+    c_source_path = File.join(@tempdir, "a.c")
+
+    write_file c_source_path do |io|
+      io.write <<-C
+        #include <ruby.h>
+        void Init_a() { }
+      C
+    end
+
+    package_path = Gem::Package.build @spec
+    installer = Gem::Installer.at(package_path)
+
+    # Make sure the gem is installed and backup the correct package
+
+    installer.install
+
+    package_bkp_path = "#{package_path}.bkp"
+    FileUtils.cp package_path, package_bkp_path
+
+    # Break the extension, rebuild it, and try to install it
+
+    write_file c_source_path do |io|
+      io.write "typo"
+    end
+
+    Gem::Package.build @spec
+
+    assert_raise Gem::Ext::BuildError do
+      installer.install
+    end
+
+    # Make sure installing the good package again still works
+
+    FileUtils.cp "#{package_path}.bkp", package_path
+
+    Dir.chdir @tempdir do
+      inst = Gem::DependencyInstaller.new domain: :local
+      inst.install package_path
+    end
+  end
+
   def test_install_minimal_deps
     util_setup_gems
 
diff --git a/test/rubygems/test_gem_installer.rb b/test/rubygems/test_gem_installer.rb
index dfa8df283c..6d8a523507 100644
--- a/test/rubygems/test_gem_installer.rb
+++ b/test/rubygems/test_gem_installer.rb
@@ -1478,12 +1478,7 @@ end
 
     @spec = setup_base_spec
     @spec.extensions << "extconf.rb"
-    write_file File.join(@tempdir, "extconf.rb") do |io|
-      io.write <<-RUBY
-        require "mkmf"
-        create_makefile("#{@spec.name}")
-      RUBY
-    end
+    write_dummy_extconf @spec.name
 
     @spec.files += %w[extconf.rb]
 
@@ -1503,12 +1498,7 @@ end
     @spec = setup_base_spec
 
     @spec.extensions << "extconf.rb"
-    write_file File.join(@tempdir, "extconf.rb") do |io|
-      io.write <<-RUBY
-        require "mkmf"
-        create_makefile("#{@spec.name}")
-      RUBY
-    end
+    write_dummy_extconf @spec.name
 
     @spec.files += %w[extconf.rb]
 
@@ -1539,12 +1529,7 @@ end
   def test_install_user_extension_dir
     @spec = setup_base_spec
     @spec.extensions << "extconf.rb"
-    write_file File.join(@tempdir, "extconf.rb") do |io|
-      io.write <<-RUBY
-        require "mkmf"
-        create_makefile("#{@spec.name}")
-      RUBY
-    end
+    write_dummy_extconf @spec.name
 
     @spec.files += %w[extconf.rb]
 
@@ -1571,15 +1556,13 @@ end
 
     @spec = setup_base_spec
     @spec.extensions << "extconf.rb"
-    write_file File.join(@tempdir, "extconf.rb") do |io|
+    write_dummy_extconf @spec.name do |io|
       io.write <<-RUBY
-        require "mkmf"
 
         CONFIG['CC'] = '$(TOUCH) $@ ||'
         CONFIG['LDSHARED'] = '$(TOUCH) $@ ||'
         $ruby = '#{Gem.ruby}'
 
-        create_makefile("#{@spec.name}")
       RUBY
     end
 
@@ -1618,12 +1601,7 @@ end
 
     @spec = setup_base_spec
     @spec.extensions << "extconf.rb"
-    write_file File.join(@tempdir, "extconf.rb") do |io|
-      io.write <<-RUBY
-        require "mkmf"
-        create_makefile("#{@spec.name}")
-      RUBY
-    end
+    write_dummy_extconf @spec.name
 
     rb = File.join("lib", "#{@spec.name}.rb")
     @spec.files += [rb]
@@ -1663,15 +1641,13 @@ end
 
       @spec.extensions << "extconf.rb"
 
-      write_file File.join(@tempdir, "extconf.rb") do |io|
+      write_dummy_extconf @spec.name do |io|
         io.write <<-RUBY
-          require "mkmf"
 
           CONFIG['CC'] = '$(TOUCH) $@ ||'
           CONFIG['LDSHARED'] = '$(TOUCH) $@ ||'
           $ruby = '#{Gem.ruby}'
 
-          create_makefile("#{@spec.name}")
         RUBY
       end
 
@@ -1698,13 +1674,13 @@ end
     @spec.require_paths = ["."]
     @spec.extensions << "extconf.rb"
 
-    File.write File.join(@tempdir, "extconf.rb"), <<-RUBY
-      require "mkmf"
-      CONFIG['CC'] = '$(TOUCH) $@ ||'
-      CONFIG['LDSHARED'] = '$(TOUCH) $@ ||'
-      $ruby = '#{Gem.ruby}'
-      create_makefile("#{@spec.name}")
-    RUBY
+    write_dummy_extconf @spec.name do |io|
+      io.write <<~RUBY
+        CONFIG['CC'] = '$(TOUCH) $@ ||'
+        CONFIG['LDSHARED'] = '$(TOUCH) $@ ||'
+        $ruby = '#{Gem.ruby}'
+      RUBY
+    end
 
     # empty depend file for no auto dependencies
     @spec.files += %W[depend #{@spec.name}.c].each do |file|
diff --git a/test/socket/test_socket.rb b/test/socket/test_socket.rb
index 165990dd64..4b85d43291 100644
--- a/test/socket/test_socket.rb
+++ b/test/socket/test_socket.rb
@@ -937,6 +937,32 @@ class TestSocket < Test::Unit::TestCase
     RUBY
   end
 
+  def test_tcp_socket_open_timeout
+    opts = %w[-rsocket -W1]
+    assert_separately opts, <<~RUBY
+    Addrinfo.define_singleton_method(:getaddrinfo) do |_, _, family, *_|
+      if family == Socket::AF_INET6
+        sleep
+      else
+        [Addrinfo.tcp("127.0.0.1", 12345)]
+      end
+    end
+
+    assert_raise(Errno::ETIMEDOUT) do
+      Socket.tcp("localhost", 12345, open_timeout: 0.01)
+    end
+    RUBY
+  end
+
+  def test_tcp_socket_open_timeout_with_other_timeouts
+    opts = %w[-rsocket -W1]
+    assert_separately opts, <<~RUBY
+    assert_raise(ArgumentError) do
+      Socket.tcp("localhost", 12345, open_timeout: 0.01, resolv_timout: 0.01)
+    end
+    RUBY
+  end
+
   def test_tcp_socket_one_hostname_resolution_succeeded_at_least
     opts = %w[-rsocket -W1]
     assert_separately opts, <<~RUBY