Update to ruby/spec@cd1b911

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59093 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

53 files changed, 316 insertions, 423 deletions

diff --git a/spec/rubyspec/appveyor.yml b/spec/rubyspec/appveyor.yml
index b139c74081..544bea7d1b 100644
--- a/spec/rubyspec/appveyor.yml
+++ b/spec/rubyspec/appveyor.yml
@@ -7,11 +7,12 @@ environment:
 install:
   - SET PATH=C:\Ruby%RUBY_VERSION%\bin;%PATH%
   - ruby --version
+  - call "C:\Ruby23-x64\DevKit\devkitvars.bat"
   - git clone https://github.com/ruby/mspec.git ../mspec
 build: off
 test_script:
   - SET CHECK_LEAKS=true
-  - ../mspec/bin/mspec -ff command_line language core library
+  - ../mspec/bin/mspec -ff
 branches:
   only:
     - master
diff --git a/spec/rubyspec/core/kernel/fixtures/classes.rb b/spec/rubyspec/core/kernel/fixtures/classes.rb
index fa6d8baf0b..c4a4d00485 100644
--- a/spec/rubyspec/core/kernel/fixtures/classes.rb
+++ b/spec/rubyspec/core/kernel/fixtures/classes.rb
@@ -213,22 +213,6 @@ module KernelSpecs
     end
   end
 
-  module KernelBlockGiven
-    def self.accept_block
-      Kernel.block_given?
-    end
-
-    def self.accept_block_as_argument(&block)
-      Kernel.block_given?
-    end
-
-    class << self
-      define_method(:defined_block) do
-        Kernel.block_given?
-      end
-    end
-  end
-
   module SelfBlockGiven
     def self.accept_block
       self.send(:block_given?)
diff --git a/spec/rubyspec/core/kernel/yield_self_spec.rb b/spec/rubyspec/core/kernel/yield_self_spec.rb
new file mode 100644
index 0000000000..817c01f288
--- /dev/null
+++ b/spec/rubyspec/core/kernel/yield_self_spec.rb
@@ -0,0 +1,26 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+has_yield_self = VersionGuard.new("2.5").match? || PlatformGuard.implementation?(:truffleruby)
+
+if has_yield_self
+  describe "Kernel#yield_self" do
+    it "yields self" do
+      object = Object.new
+      object.yield_self { |o| o.should equal object }
+    end
+
+    it "returns the block return value" do
+      object = Object.new
+      object.yield_self { 42 }.should equal 42
+    end
+
+    it "returns a sized Enumerator when no block given" do
+      object = Object.new
+      enum = object.yield_self
+      enum.should be_an_instance_of Enumerator
+      enum.size.should equal 1
+      enum.peek.should equal object
+      enum.first.should equal object
+    end
+  end
+end
diff --git a/spec/rubyspec/core/string/split_spec.rb b/spec/rubyspec/core/string/split_spec.rb
index 7d7d383f9c..1a4128f828 100644
--- a/spec/rubyspec/core/string/split_spec.rb
+++ b/spec/rubyspec/core/string/split_spec.rb
@@ -300,6 +300,10 @@ describe "String#split with Regexp" do
     "AabB".split(/([a-z])+/).should == ["A", "b", "B"]
   end
 
+  it "applies the limit to the number of split substrings, without counting captures" do
+    "aBaBa".split(/(B)()()/, 2).should == ["a", "B", "", "", "aBa"]
+  end
+
   it "does not include non-matching captures in the result array" do
     "hello".split(/(el)|(xx)/).should == ["h", "el", "lo"]
   end
diff --git a/spec/rubyspec/library/net/ftp/fixtures/server.rb b/spec/rubyspec/library/net/ftp/fixtures/server.rb
index 69dc151333..2129835883 100644
--- a/spec/rubyspec/library/net/ftp/fixtures/server.rb
+++ b/spec/rubyspec/library/net/ftp/fixtures/server.rb
@@ -8,9 +8,9 @@ module NetFTPSpecs
     # port number
     attr_reader :server_port
 
-    def initialize(hostname = "localhost", server_port = 0)
-      @hostname = hostname
-      @server = TCPServer.new(@hostname, server_port)
+    def initialize
+      @hostname = "localhost"
+      @server = TCPServer.new(@hostname, 0)
       @server_port = @server.addr[1]
 
       @handlers = {}
diff --git a/spec/rubyspec/library/net/http/http/fixtures/http_server.rb b/spec/rubyspec/library/net/http/http/fixtures/http_server.rb
index 9c6fe2696f..c2ae2360d3 100644
--- a/spec/rubyspec/library/net/http/http/fixtures/http_server.rb
+++ b/spec/rubyspec/library/net/http/http/fixtures/http_server.rb
@@ -47,7 +47,8 @@ module NetHTTPSpecs
     @server_thread = nil
 
     def port
-      @server ? @server.config[:Port] : 3333
+      raise "server not started" unless @server
+      @server.config[:Port]
     end
 
     def start_server
@@ -79,9 +80,11 @@ module NetHTTPSpecs
         rescue Errno::EPIPE
           # Because WEBrick is not thread-safe and only catches IOError
         end
+        @server = nil
       end
       if @server_thread
         @server_thread.join
+        @server_thread = nil
       end
       timeout = WEBrick::Utils::TimeoutHandler
       timeout.terminate if timeout.respond_to?(:terminate)
diff --git a/spec/rubyspec/library/readline/spec_helper.rb b/spec/rubyspec/library/readline/spec_helper.rb
index b5ac16d22a..04ab0f755f 100644
--- a/spec/rubyspec/library/readline/spec_helper.rb
+++ b/spec/rubyspec/library/readline/spec_helper.rb
@@ -1,13 +1,11 @@
 require File.expand_path('../../../spec_helper', __FILE__)
 
-unless MSpec.retrieve(:features).key?(:readline)
-  begin
-    require 'readline'
-  rescue LoadError
-  else
-    # rb-readline behaves quite differently
-    if $".grep(/\brbreadline\.rb$/).empty?
-      MSpec.enable_feature :readline
-    end
+begin
+  require 'readline'
+rescue LoadError
+else
+  # rb-readline behaves quite differently
+  unless defined?(RbReadline)
+    MSpec.enable_feature :readline
   end
 end
diff --git a/spec/rubyspec/library/socket/addrinfo/bind_spec.rb b/spec/rubyspec/library/socket/addrinfo/bind_spec.rb
index 4afa3a0211..c892b05756 100644
--- a/spec/rubyspec/library/socket/addrinfo/bind_spec.rb
+++ b/spec/rubyspec/library/socket/addrinfo/bind_spec.rb
@@ -5,7 +5,7 @@ require 'socket'
 describe "Addrinfo#bind" do
 
   before :each do
-    @addrinfo = Addrinfo.tcp("127.0.0.1", SocketSpecs.port)
+    @addrinfo = Addrinfo.tcp("127.0.0.1", 0)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/basicsocket/close_read_spec.rb b/spec/rubyspec/library/socket/basicsocket/close_read_spec.rb
index d0b73c88ad..c71e1acaf9 100644
--- a/spec/rubyspec/library/socket/basicsocket/close_read_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/close_read_spec.rb
@@ -3,7 +3,7 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "Socket::BasicSocket#close_read" do
   before :each do
-    @server = TCPServer.new(SocketSpecs.port)
+    @server = TCPServer.new(0)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/basicsocket/close_write_spec.rb b/spec/rubyspec/library/socket/basicsocket/close_write_spec.rb
index 7cba1caa8f..a00f5d5870 100644
--- a/spec/rubyspec/library/socket/basicsocket/close_write_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/close_write_spec.rb
@@ -3,7 +3,7 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "Socket::BasicSocket#close_write" do
   before :each do
-    @server = TCPServer.new(SocketSpecs.port)
+    @server = TCPServer.new(0)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/basicsocket/do_not_reverse_lookup_spec.rb b/spec/rubyspec/library/socket/basicsocket/do_not_reverse_lookup_spec.rb
index 0875c1eca1..3ef3a686e2 100644
--- a/spec/rubyspec/library/socket/basicsocket/do_not_reverse_lookup_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/do_not_reverse_lookup_spec.rb
@@ -4,8 +4,9 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "BasicSocket.do_not_reverse_lookup" do
   before :each do
     @do_not_reverse_lookup = BasicSocket.do_not_reverse_lookup
-    @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
-    @socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+    @server = TCPServer.new('127.0.0.1', 0)
+    @port = @server.addr[1]
+    @socket = TCPSocket.new('127.0.0.1', @port)
   end
 
   after :each do
@@ -21,7 +22,7 @@ describe "BasicSocket.do_not_reverse_lookup" do
   it "causes 'peeraddr' to avoid name lookups" do
     @socket.do_not_reverse_lookup = true
     BasicSocket.do_not_reverse_lookup = true
-    @socket.peeraddr.should == ["AF_INET", SocketSpecs.port, "127.0.0.1", "127.0.0.1"]
+    @socket.peeraddr.should == ["AF_INET", @port, "127.0.0.1", "127.0.0.1"]
   end
 
   it "looks for hostnames when set to false" do
diff --git a/spec/rubyspec/library/socket/basicsocket/for_fd_spec.rb b/spec/rubyspec/library/socket/basicsocket/for_fd_spec.rb
index 5ad1ea84d0..164e4dc93c 100644
--- a/spec/rubyspec/library/socket/basicsocket/for_fd_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/for_fd_spec.rb
@@ -4,7 +4,7 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "BasicSocket#for_fd" do
   before :each do
-    @server = TCPServer.new(SocketSpecs.port)
+    @server = TCPServer.new(0)
     @s2 = nil
   end
 
diff --git a/spec/rubyspec/library/socket/basicsocket/getpeername_spec.rb b/spec/rubyspec/library/socket/basicsocket/getpeername_spec.rb
index 1edfbcd3ec..cecf590092 100644
--- a/spec/rubyspec/library/socket/basicsocket/getpeername_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/getpeername_spec.rb
@@ -4,8 +4,9 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "Socket::BasicSocket#getpeername" do
 
   before :each do
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
-    @client = TCPSocket.new("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
+    @client = TCPSocket.new("127.0.0.1", @port)
   end
 
   after :each do
@@ -14,7 +15,7 @@ describe "Socket::BasicSocket#getpeername" do
   end
 
   it "returns the sockaddr of the other end of the connection" do
-    server_sockaddr = Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1")
+    server_sockaddr = Socket.pack_sockaddr_in(@port, "127.0.0.1")
     @client.getpeername.should == server_sockaddr
   end
 
diff --git a/spec/rubyspec/library/socket/basicsocket/getsockname_spec.rb b/spec/rubyspec/library/socket/basicsocket/getsockname_spec.rb
index 6d30286733..8f8616bd2b 100644
--- a/spec/rubyspec/library/socket/basicsocket/getsockname_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/getsockname_spec.rb
@@ -8,16 +8,16 @@ describe "Socket::BasicSocket#getsockname" do
   end
 
   it "returns the sockaddr associacted with the socket" do
-    @socket = TCPServer.new("127.0.0.1", SocketSpecs.port)
+    @socket = TCPServer.new("127.0.0.1", 0)
     sockaddr = Socket.unpack_sockaddr_in(@socket.getsockname)
-    sockaddr.should == [SocketSpecs.port, "127.0.0.1"]
+    sockaddr.should == [@socket.addr[1], "127.0.0.1"]
  end
 
   it "works on sockets listening in ipaddr_any" do
-    @socket = TCPServer.new(SocketSpecs.port)
+    @socket = TCPServer.new(0)
     sockaddr = Socket.unpack_sockaddr_in(@socket.getsockname)
     ["::", "0.0.0.0", "::ffff:0.0.0.0"].include?(sockaddr[1]).should be_true
-    sockaddr[0].should == SocketSpecs.port
+    sockaddr[0].should == @socket.addr[1]
   end
 
   it "returns empty sockaddr for unbinded sockets" do
diff --git a/spec/rubyspec/library/socket/basicsocket/recv_spec.rb b/spec/rubyspec/library/socket/basicsocket/recv_spec.rb
index 5ac274f6d8..5891bf9c87 100644
--- a/spec/rubyspec/library/socket/basicsocket/recv_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/recv_spec.rb
@@ -5,7 +5,8 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "BasicSocket#recv" do
 
   before :each do
-    @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
+    @server = TCPServer.new('127.0.0.1', 0)
+    @port = @server.addr[1]
   end
 
   after :each do
@@ -23,7 +24,7 @@ describe "BasicSocket#recv" do
     Thread.pass while t.status and t.status != "sleep"
     t.status.should_not be_nil
 
-    socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+    socket = TCPSocket.new('127.0.0.1', @port)
     socket.send('hello', 0)
     socket.close
 
@@ -46,7 +47,7 @@ describe "BasicSocket#recv" do
       Thread.pass while t.status and t.status != "sleep"
       t.status.should_not be_nil
 
-      socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+      socket = TCPSocket.new('127.0.0.1', @port)
       socket.send('helloU', Socket::MSG_OOB)
       socket.shutdown(1)
       t.join
@@ -67,7 +68,7 @@ describe "BasicSocket#recv" do
     Thread.pass while t.status and t.status != "sleep"
     t.status.should_not be_nil
 
-    socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+    socket = TCPSocket.new('127.0.0.1', @port)
     socket.write("firstline\377secondline\377")
     socket.close
 
@@ -77,7 +78,7 @@ describe "BasicSocket#recv" do
 
   ruby_version_is "2.3" do
     it "allows an output buffer as third argument" do
-      socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+      socket = TCPSocket.new('127.0.0.1', @port)
       socket.write("data")
 
       client = @server.accept
diff --git a/spec/rubyspec/library/socket/basicsocket/send_spec.rb b/spec/rubyspec/library/socket/basicsocket/send_spec.rb
index 7822f4696b..4df0d04a10 100644
--- a/spec/rubyspec/library/socket/basicsocket/send_spec.rb
+++ b/spec/rubyspec/library/socket/basicsocket/send_spec.rb
@@ -3,8 +3,9 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "BasicSocket#send" do
   before :each do
-    @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
-    @socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+    @server = TCPServer.new('127.0.0.1', 0)
+    @port = @server.addr[1]
+    @socket = TCPSocket.new('127.0.0.1', @port)
   end
 
   after :each do
@@ -74,7 +75,7 @@ describe "BasicSocket#send" do
      Thread.pass while t.status and t.status != "sleep"
      t.status.should_not be_nil
 
-     sockaddr = Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1")
+     sockaddr = Socket.pack_sockaddr_in(@port, "127.0.0.1")
      @socket.send('hello', 0, sockaddr).should == 5
      @socket.shutdown # indicate, that we are done sending
 
diff --git a/spec/rubyspec/library/socket/fixtures/classes.rb b/spec/rubyspec/library/socket/fixtures/classes.rb
index 6828f9fad5..b8e5d2a38d 100644
--- a/spec/rubyspec/library/socket/fixtures/classes.rb
+++ b/spec/rubyspec/library/socket/fixtures/classes.rb
@@ -23,29 +23,6 @@ module SocketSpecs
     Socket.getaddrinfo(host, nil)[0][3]
   end
 
-  def self.find_available_port
-    begin
-      s = TCPServer.open(0)
-      port = s.addr[1]
-      s.close
-      port
-    rescue
-      43191
-    end
-  end
-
-  def self.port
-    @port ||= find_available_port
-  end
-
-  def self.str_port
-    port.to_s
-  end
-
-  def self.local_port
-    find_available_port
-  end
-
   def self.reserved_unused_port
     # https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
     0
diff --git a/spec/rubyspec/library/socket/ipsocket/addr_spec.rb b/spec/rubyspec/library/socket/ipsocket/addr_spec.rb
index 2ac4c3d413..2184082c51 100644
--- a/spec/rubyspec/library/socket/ipsocket/addr_spec.rb
+++ b/spec/rubyspec/library/socket/ipsocket/addr_spec.rb
@@ -4,7 +4,7 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "Socket::IPSocket#addr" do
   before :each do
     @do_not_reverse_lookup = BasicSocket.do_not_reverse_lookup
-    @socket = TCPServer.new("127.0.0.1", SocketSpecs.port)
+    @socket = TCPServer.new("127.0.0.1", 0)
   end
 
   after :each do
@@ -17,7 +17,7 @@ describe "Socket::IPSocket#addr" do
     BasicSocket.do_not_reverse_lookup = false
     addrinfo = @socket.addr
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should be_kind_of(Integer)
     addrinfo[2].should == SocketSpecs.hostname
     addrinfo[3].should == "127.0.0.1"
   end
@@ -27,7 +27,7 @@ describe "Socket::IPSocket#addr" do
     BasicSocket.do_not_reverse_lookup = true
     addrinfo = @socket.addr
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should be_kind_of(Integer)
     addrinfo[2].should == "127.0.0.1"
     addrinfo[3].should == "127.0.0.1"
   end
@@ -35,7 +35,7 @@ describe "Socket::IPSocket#addr" do
   it "returns an address in the array if passed false" do
     addrinfo = @socket.addr(false)
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should be_kind_of(Integer)
     addrinfo[2].should == "127.0.0.1"
     addrinfo[3].should == "127.0.0.1"
   end
diff --git a/spec/rubyspec/library/socket/ipsocket/peeraddr_spec.rb b/spec/rubyspec/library/socket/ipsocket/peeraddr_spec.rb
index 01b697bd27..dfd4e050ce 100644
--- a/spec/rubyspec/library/socket/ipsocket/peeraddr_spec.rb
+++ b/spec/rubyspec/library/socket/ipsocket/peeraddr_spec.rb
@@ -4,8 +4,9 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "Socket::IPSocket#peeraddr" do
   before :each do
     @do_not_reverse_lookup = BasicSocket.do_not_reverse_lookup
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
-    @client = TCPSocket.new("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
+    @client = TCPSocket.new("127.0.0.1", @port)
   end
 
   after :each do
@@ -23,7 +24,7 @@ describe "Socket::IPSocket#peeraddr" do
     BasicSocket.do_not_reverse_lookup = false
     addrinfo = @client.peeraddr
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should == @port
     addrinfo[2].should == SocketSpecs.hostname
     addrinfo[3].should == "127.0.0.1"
   end
@@ -33,7 +34,7 @@ describe "Socket::IPSocket#peeraddr" do
     BasicSocket.do_not_reverse_lookup = true
     addrinfo = @client.peeraddr
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should == @port
     addrinfo[2].should == "127.0.0.1"
     addrinfo[3].should == "127.0.0.1"
   end
@@ -41,7 +42,7 @@ describe "Socket::IPSocket#peeraddr" do
   it "returns an IP instead of hostname if passed false" do
     addrinfo = @client.peeraddr(false)
     addrinfo[0].should == "AF_INET"
-    addrinfo[1].should == SocketSpecs.port
+    addrinfo[1].should == @port
     addrinfo[2].should == "127.0.0.1"
     addrinfo[3].should == "127.0.0.1"
   end
diff --git a/spec/rubyspec/library/socket/ipsocket/recvfrom_spec.rb b/spec/rubyspec/library/socket/ipsocket/recvfrom_spec.rb
index ccf7b1cc51..54f150decf 100644
--- a/spec/rubyspec/library/socket/ipsocket/recvfrom_spec.rb
+++ b/spec/rubyspec/library/socket/ipsocket/recvfrom_spec.rb
@@ -4,8 +4,9 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "Socket::IPSocket#recvfrom" do
 
   before :each do
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
-    @client = TCPSocket.new("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
+    @client = TCPSocket.new("127.0.0.1", @port)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/shared/partially_closable_sockets.rb b/spec/rubyspec/library/socket/shared/partially_closable_sockets.rb
index 1309f15f85..1bdff08bf6 100644
--- a/spec/rubyspec/library/socket/shared/partially_closable_sockets.rb
+++ b/spec/rubyspec/library/socket/shared/partially_closable_sockets.rb
@@ -1,11 +1,11 @@
 describe "partially closable sockets", shared: true do
-  specify "if the write end is closed then the other side can read past EOF without blocking" do
+  it "if the write end is closed then the other side can read past EOF without blocking" do
     @s1.write("foo")
     @s1.close_write
     @s2.read("foo".size + 1).should == "foo"
   end
 
-  specify "closing the write end ensures that the other side can read until EOF" do
+  it "closing the write end ensures that the other side can read until EOF" do
     @s1.write("hello world")
     @s1.close_write
     @s2.read.should == "hello world"
diff --git a/spec/rubyspec/library/socket/shared/recv_nonblock.rb b/spec/rubyspec/library/socket/shared/recv_nonblock.rb
index 4a63b16024..a5f6c6812e 100644
--- a/spec/rubyspec/library/socket/shared/recv_nonblock.rb
+++ b/spec/rubyspec/library/socket/shared/recv_nonblock.rb
@@ -10,7 +10,7 @@ describe :socket_recv_nonblock, shared: true do
   end
 
   it "raises an exception extending IO::WaitReadable if there's no data available" do
-    @s1.bind(Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1"))
+    @s1.bind(Socket.pack_sockaddr_in(0, "127.0.0.1"))
     lambda {
       @s1.recv_nonblock(5)
     }.should raise_error(IO::WaitReadable) { |e|
@@ -24,7 +24,7 @@ describe :socket_recv_nonblock, shared: true do
   end
 
   it "receives data after it's ready" do
-    @s1.bind(Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1"))
+    @s1.bind(Socket.pack_sockaddr_in(0, "127.0.0.1"))
     @s2.send("aaa", 0, @s1.getsockname)
     IO.select([@s1], nil, nil, 2)
     @s1.recv_nonblock(5).should == "aaa"
@@ -32,7 +32,7 @@ describe :socket_recv_nonblock, shared: true do
 
   ruby_version_is "2.3" do
     it "allows an output buffer as third argument" do
-      @s1.bind(Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1"))
+      @s1.bind(Socket.pack_sockaddr_in(0, "127.0.0.1"))
       @s2.send("data", 0, @s1.getsockname)
       IO.select([@s1], nil, nil, 2)
 
@@ -43,7 +43,7 @@ describe :socket_recv_nonblock, shared: true do
   end
 
   it "does not block if there's no data available" do
-    @s1.bind(Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1"))
+    @s1.bind(Socket.pack_sockaddr_in(0, "127.0.0.1"))
     @s2.send("a", 0, @s1.getsockname)
     IO.select([@s1], nil, nil, 2)
     @s1.recv_nonblock(1).should == "a"
diff --git a/spec/rubyspec/library/socket/socket/bind_spec.rb b/spec/rubyspec/library/socket/socket/bind_spec.rb
index 57dff3bd6d..399c988b32 100644
--- a/spec/rubyspec/library/socket/socket/bind_spec.rb
+++ b/spec/rubyspec/library/socket/socket/bind_spec.rb
@@ -5,8 +5,8 @@ include Socket::Constants
 
 describe "Socket#bind on SOCK_DGRAM socket" do
   before :each do
-    @sock = Socket.new(AF_INET, SOCK_DGRAM, 0);
-    @sockaddr = Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1");
+    @sock = Socket.new(AF_INET, SOCK_DGRAM, 0)
+    @sockaddr = Socket.pack_sockaddr_in(0, "127.0.0.1")
   end
 
   after :each do
@@ -22,30 +22,30 @@ describe "Socket#bind on SOCK_DGRAM socket" do
     @sock.bind(@sockaddr).should == 0
   end
 
-  it "raises Errno::EINVAL when binding to an already bound port" do
-    @sock.bind(@sockaddr);
+  it "raises Errno::EINVAL when already bound" do
+    @sock.bind(@sockaddr)
 
-    lambda { @sock.bind(@sockaddr); }.should raise_error(Errno::EINVAL);
+    lambda { @sock.bind(@sockaddr) }.should raise_error(Errno::EINVAL)
   end
 
   it "raises Errno::EADDRNOTAVAIL when the specified sockaddr is not available from the local machine" do
-    sockaddr1 = Socket.pack_sockaddr_in(SocketSpecs.port, "4.3.2.1");
-    lambda { @sock.bind(sockaddr1); }.should raise_error(Errno::EADDRNOTAVAIL)
+    sockaddr1 = Socket.pack_sockaddr_in(0, "4.3.2.1")
+    lambda { @sock.bind(sockaddr1) }.should raise_error(Errno::EADDRNOTAVAIL)
   end
 
   platform_is_not :windows, :cygwin do
     it "raises Errno::EACCES when the current user does not have permission to bind" do
-      sockaddr1 = Socket.pack_sockaddr_in(1, "127.0.0.1");
-      lambda { @sock.bind(sockaddr1); }.should raise_error(Errno::EACCES)
+      sockaddr1 = Socket.pack_sockaddr_in(1, "127.0.0.1")
+      lambda { @sock.bind(sockaddr1) }.should raise_error(Errno::EACCES)
     end
   end
 end
 
 describe "Socket#bind on SOCK_STREAM socket" do
   before :each do
-    @sock = Socket.new(AF_INET, SOCK_STREAM, 0);
+    @sock = Socket.new(AF_INET, SOCK_STREAM, 0)
     @sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, true)
-    @sockaddr = Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1");
+    @sockaddr = Socket.pack_sockaddr_in(0, "127.0.0.1")
   end
 
   after :each do
@@ -61,21 +61,21 @@ describe "Socket#bind on SOCK_STREAM socket" do
     @sock.bind(@sockaddr).should == 0
   end
 
-  it "raises Errno::EINVAL when binding to an already bound port" do
-    @sock.bind(@sockaddr);
+  it "raises Errno::EINVAL when already bound" do
+    @sock.bind(@sockaddr)
 
-    lambda { @sock.bind(@sockaddr); }.should raise_error(Errno::EINVAL);
+    lambda { @sock.bind(@sockaddr) }.should raise_error(Errno::EINVAL)
   end
 
   it "raises Errno::EADDRNOTAVAIL when the specified sockaddr is not available from the local machine" do
-    sockaddr1 = Socket.pack_sockaddr_in(SocketSpecs.port, "4.3.2.1");
-    lambda { @sock.bind(sockaddr1); }.should raise_error(Errno::EADDRNOTAVAIL)
+    sockaddr1 = Socket.pack_sockaddr_in(0, "4.3.2.1")
+    lambda { @sock.bind(sockaddr1) }.should raise_error(Errno::EADDRNOTAVAIL)
   end
 
   platform_is_not :windows, :cygwin do
     it "raises Errno::EACCES when the current user does not have permission to bind" do
-      sockaddr1 = Socket.pack_sockaddr_in(1, "127.0.0.1");
-      lambda { @sock.bind(sockaddr1); }.should raise_error(Errno::EACCES)
+      sockaddr1 = Socket.pack_sockaddr_in(1, "127.0.0.1")
+      lambda { @sock.bind(sockaddr1) }.should raise_error(Errno::EACCES)
     end
   end
 end
diff --git a/spec/rubyspec/library/socket/socket/connect_nonblock_spec.rb b/spec/rubyspec/library/socket/socket/connect_nonblock_spec.rb
index 77c2340688..fd92c0740c 100644
--- a/spec/rubyspec/library/socket/socket/connect_nonblock_spec.rb
+++ b/spec/rubyspec/library/socket/socket/connect_nonblock_spec.rb
@@ -6,7 +6,8 @@ require 'socket'
 describe "Socket#connect_nonblock" do
   before :each do
     @hostname = "127.0.0.1"
-    @addr = Socket.sockaddr_in(SocketSpecs.port, @hostname)
+    @server = TCPServer.new(@hostname, 0) # started, but no accept
+    @addr = Socket.sockaddr_in(@server.addr[1], @hostname)
     @socket = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
     @thread = nil
   end
@@ -17,27 +18,31 @@ describe "Socket#connect_nonblock" do
   end
 
   it "connects the socket to the remote side" do
-    ready = false
+    port = nil
+    accept = false
     @thread = Thread.new do
-      server = TCPServer.new(@hostname, SocketSpecs.port)
-      ready = true
+      server = TCPServer.new(@hostname, 0)
+      port = server.addr[1]
+      Thread.pass until accept
       conn = server.accept
       conn << "hello!"
       conn.close
       server.close
     end
 
-    Thread.pass while (@thread.status and @thread.status != 'sleep') or !ready
+    Thread.pass until port
 
+    addr = Socket.sockaddr_in(port, @hostname)
     begin
-      @socket.connect_nonblock(@addr)
+      @socket.connect_nonblock(addr)
     rescue Errno::EINPROGRESS
     end
 
+    accept = true
     IO.select nil, [@socket]
 
     begin
-      @socket.connect_nonblock(@addr)
+      @socket.connect_nonblock(addr)
     rescue Errno::EISCONN
       # Not all OS's use this errno, so we trap and ignore it
     end
diff --git a/spec/rubyspec/library/socket/socket/for_fd_spec.rb b/spec/rubyspec/library/socket/socket/for_fd_spec.rb
index 7f3cfcceb4..6688988448 100644
--- a/spec/rubyspec/library/socket/socket/for_fd_spec.rb
+++ b/spec/rubyspec/library/socket/socket/for_fd_spec.rb
@@ -4,8 +4,9 @@ require 'socket'
 
 describe "Socket.for_fd" do
   before :each do
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
-    @client = TCPSocket.open("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
+    @client = TCPSocket.open("127.0.0.1", @port)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/socket/getnameinfo_spec.rb b/spec/rubyspec/library/socket/socket/getnameinfo_spec.rb
index 2b0ea4a723..9fc55dd61b 100644
--- a/spec/rubyspec/library/socket/socket/getnameinfo_spec.rb
+++ b/spec/rubyspec/library/socket/socket/getnameinfo_spec.rb
@@ -14,9 +14,9 @@ describe "Socket.getnameinfo" do
   end
 
   it "gets the name information and don't resolve it" do
-    sockaddr = Socket.sockaddr_in SocketSpecs.port, '127.0.0.1'
+    sockaddr = Socket.sockaddr_in 3333, '127.0.0.1'
     name_info = Socket.getnameinfo(sockaddr, Socket::NI_NUMERICHOST | Socket::NI_NUMERICSERV)
-    name_info.should == ['127.0.0.1', "#{SocketSpecs.port}"]
+    name_info.should == ['127.0.0.1', "3333"]
   end
 
   def should_be_valid_dns_name(name)
@@ -28,10 +28,10 @@ describe "Socket.getnameinfo" do
   end
 
   it "gets the name information and resolve the host" do
-    sockaddr = Socket.sockaddr_in SocketSpecs.port, '127.0.0.1'
+    sockaddr = Socket.sockaddr_in 3333, '127.0.0.1'
     name_info = Socket.getnameinfo(sockaddr, Socket::NI_NUMERICSERV)
     should_be_valid_dns_name(name_info[0])
-    name_info[1].should == SocketSpecs.port.to_s
+    name_info[1].should == 3333.to_s
   end
 
   it "gets the name information and resolves the service" do
@@ -44,8 +44,8 @@ describe "Socket.getnameinfo" do
   end
 
   it "gets a 3-element array and doesn't resolve hostname" do
-    name_info = Socket.getnameinfo(["AF_INET", SocketSpecs.port, '127.0.0.1'], Socket::NI_NUMERICHOST | Socket::NI_NUMERICSERV)
-    name_info.should == ['127.0.0.1', "#{SocketSpecs.port}"]
+    name_info = Socket.getnameinfo(["AF_INET", 3333, '127.0.0.1'], Socket::NI_NUMERICHOST | Socket::NI_NUMERICSERV)
+    name_info.should == ['127.0.0.1', "3333"]
   end
 
   it "gets a 3-element array and resolves the service" do
@@ -54,8 +54,8 @@ describe "Socket.getnameinfo" do
   end
 
   it "gets a 4-element array and doesn't resolve hostname" do
-    name_info = Socket.getnameinfo(["AF_INET", SocketSpecs.port, 'foo', '127.0.0.1'], Socket::NI_NUMERICHOST | Socket::NI_NUMERICSERV)
-    name_info.should == ['127.0.0.1', "#{SocketSpecs.port}"]
+    name_info = Socket.getnameinfo(["AF_INET", 3333, 'foo', '127.0.0.1'], Socket::NI_NUMERICHOST | Socket::NI_NUMERICSERV)
+    name_info.should == ['127.0.0.1', "3333"]
   end
 
   it "gets a 4-element array and resolves the service" do
diff --git a/spec/rubyspec/library/socket/socket/listen_spec.rb b/spec/rubyspec/library/socket/socket/listen_spec.rb
index ebc97954fb..bea87f4ec5 100644
--- a/spec/rubyspec/library/socket/socket/listen_spec.rb
+++ b/spec/rubyspec/library/socket/socket/listen_spec.rb
@@ -14,7 +14,7 @@ describe "Socket#listen" do
   end
 
   it "verifies we can listen for incoming connections" do
-    sockaddr = Socket.pack_sockaddr_in(SocketSpecs.port, "127.0.0.1")
+    sockaddr = Socket.pack_sockaddr_in(0, "127.0.0.1")
     @socket.setsockopt(Socket::SOL_SOCKET, Socket::SO_REUSEADDR, true)
     @socket.bind(sockaddr)
     @socket.listen(1).should == 0
diff --git a/spec/rubyspec/library/socket/socket/unpack_sockaddr_in_spec.rb b/spec/rubyspec/library/socket/socket/unpack_sockaddr_in_spec.rb
index 2df3b69a6d..91d2b947a1 100644
--- a/spec/rubyspec/library/socket/socket/unpack_sockaddr_in_spec.rb
+++ b/spec/rubyspec/library/socket/socket/unpack_sockaddr_in_spec.rb
@@ -5,13 +5,13 @@ require 'socket'
 describe "Socket.unpack_sockaddr_in" do
 
   it "decodes the host name and port number of a packed sockaddr_in" do
-    sockaddr = Socket.sockaddr_in SocketSpecs.port, '127.0.0.1'
-    Socket.unpack_sockaddr_in(sockaddr).should == [SocketSpecs.port, '127.0.0.1']
+    sockaddr = Socket.sockaddr_in 3333, '127.0.0.1'
+    Socket.unpack_sockaddr_in(sockaddr).should == [3333, '127.0.0.1']
   end
 
   it "gets the hostname and port number from a passed Addrinfo" do
-    addrinfo = Addrinfo.tcp('127.0.0.1', SocketSpecs.port)
-    Socket.unpack_sockaddr_in(addrinfo).should == [SocketSpecs.port, '127.0.0.1']
+    addrinfo = Addrinfo.tcp('127.0.0.1', 3333)
+    Socket.unpack_sockaddr_in(addrinfo).should == [3333, '127.0.0.1']
   end
 
   platform_is_not :windows do
diff --git a/spec/rubyspec/library/socket/socket/unpack_sockaddr_un_spec.rb b/spec/rubyspec/library/socket/socket/unpack_sockaddr_un_spec.rb
index 4d558c89c4..f81d36f7e9 100644
--- a/spec/rubyspec/library/socket/socket/unpack_sockaddr_un_spec.rb
+++ b/spec/rubyspec/library/socket/socket/unpack_sockaddr_un_spec.rb
@@ -14,12 +14,12 @@ describe 'Socket.unpack_sockaddr_un' do
     end
 
     it 'raises an ArgumentError when the sin_family is not AF_UNIX' do
-      sockaddr = Socket.sockaddr_in(SocketSpecs.port, '127.0.0.1')
+      sockaddr = Socket.sockaddr_in(0, '127.0.0.1')
       lambda { Socket.unpack_sockaddr_un(sockaddr) }.should raise_error(ArgumentError)
     end
 
     it 'raises an ArgumentError when passed addrinfo is not AF_UNIX' do
-      addrinfo = Addrinfo.tcp('127.0.0.1', SocketSpecs.port)
+      addrinfo = Addrinfo.tcp('127.0.0.1', 0)
       lambda { Socket.unpack_sockaddr_un(addrinfo) }.should raise_error(ArgumentError)
     end
   end
diff --git a/spec/rubyspec/library/socket/tcpserver/accept_nonblock_spec.rb b/spec/rubyspec/library/socket/tcpserver/accept_nonblock_spec.rb
index d0f2673af3..d6f7448084 100644
--- a/spec/rubyspec/library/socket/tcpserver/accept_nonblock_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/accept_nonblock_spec.rb
@@ -3,7 +3,8 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "Socket::TCPServer.accept_nonblock" do
   before :each do
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
   end
 
   after :each do
@@ -16,13 +17,13 @@ describe "Socket::TCPServer.accept_nonblock" do
       @server.accept_nonblock
     }.should raise_error(IO::WaitReadable)
 
-    c = TCPSocket.new("127.0.0.1", SocketSpecs.port)
+    c = TCPSocket.new("127.0.0.1", @port)
     sleep 0.1
     s = @server.accept_nonblock
 
     port, address = Socket.unpack_sockaddr_in(s.getsockname)
 
-    port.should == SocketSpecs.port
+    port.should == @port
     address.should == "127.0.0.1"
     s.should be_kind_of(TCPSocket)
 
diff --git a/spec/rubyspec/library/socket/tcpserver/accept_spec.rb b/spec/rubyspec/library/socket/tcpserver/accept_spec.rb
index cf1fbbd873..f7b017d014 100644
--- a/spec/rubyspec/library/socket/tcpserver/accept_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/accept_spec.rb
@@ -4,7 +4,8 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "TCPServer#accept" do
   before :each do
-    @server = TCPServer.new("127.0.0.1", SocketSpecs.port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @port = @server.addr[1]
   end
 
   after :each do
@@ -22,7 +23,7 @@ describe "TCPServer#accept" do
     end
     Thread.pass while t.status and t.status != "sleep"
 
-    socket = TCPSocket.new('127.0.0.1', SocketSpecs.port)
+    socket = TCPSocket.new('127.0.0.1', @port)
     socket.write('hello')
     socket.shutdown(1) # we are done with sending
     socket.read.should == 'goodbye'
@@ -38,14 +39,12 @@ describe "TCPServer#accept" do
 
     # kill thread, ensure it dies in a reasonable amount of time
     t.kill
-    a = 1
-    while a < 2000
-      break unless t.alive?
-      Thread.pass
-      sleep 0.2
+    a = 0
+    while t.alive? and a < 5000
+      sleep 0.001
       a += 1
     end
-    a.should < 2000
+    a.should < 5000
   end
 
   it "can be interrupted by Thread#raise" do
diff --git a/spec/rubyspec/library/socket/tcpserver/gets_spec.rb b/spec/rubyspec/library/socket/tcpserver/gets_spec.rb
index 2f8e699a53..86ba65eae2 100644
--- a/spec/rubyspec/library/socket/tcpserver/gets_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/gets_spec.rb
@@ -3,7 +3,7 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "TCPServer#gets" do
   before :each do
-    @server = TCPServer.new(SocketSpecs.hostname, SocketSpecs.port)
+    @server = TCPServer.new(SocketSpecs.hostname, 0)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/tcpserver/listen_spec.rb b/spec/rubyspec/library/socket/tcpserver/listen_spec.rb
index 5e9b9c1090..d764b4ce70 100644
--- a/spec/rubyspec/library/socket/tcpserver/listen_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/listen_spec.rb
@@ -5,7 +5,7 @@ require 'socket'
 
 describe 'TCPServer#listen' do
   before :each do
-    @server = TCPServer.new(SocketSpecs.hostname, SocketSpecs.port)
+    @server = TCPServer.new(SocketSpecs.hostname, 0)
   end
 
   after :each do
diff --git a/spec/rubyspec/library/socket/tcpserver/new_spec.rb b/spec/rubyspec/library/socket/tcpserver/new_spec.rb
index 4b7f53a397..ddbe96d89d 100644
--- a/spec/rubyspec/library/socket/tcpserver/new_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/new_spec.rb
@@ -7,7 +7,7 @@ describe "TCPServer.new" do
   end
 
   it "binds to a host and a port" do
-    @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
+    @server = TCPServer.new('127.0.0.1', 0)
     addr = @server.addr
     addr[0].should == 'AF_INET'
     addr[1].should be_kind_of(Fixnum)
@@ -18,53 +18,52 @@ describe "TCPServer.new" do
   end
 
   it "binds to localhost and a port with either IPv4 or IPv6" do
-    @server = TCPServer.new(SocketSpecs.hostname, SocketSpecs.port)
+    @server = TCPServer.new(SocketSpecs.hostname, 0)
     addr = @server.addr
+    addr[1].should be_kind_of(Fixnum)
     if addr[0] == 'AF_INET'
-      addr[1].should == SocketSpecs.port
       addr[2].should =~ /^#{SocketSpecs.hostname}\b/
       addr[3].should == '127.0.0.1'
     else
-      addr[1].should == SocketSpecs.port
       addr[2].should =~ /^#{SocketSpecs.hostnamev6}\b/
       addr[3].should == '::1'
     end
   end
 
   it "binds to INADDR_ANY if the hostname is empty" do
-    @server = TCPServer.new('', SocketSpecs.port)
+    @server = TCPServer.new('', 0)
     addr = @server.addr
     addr[0].should == 'AF_INET'
-    addr[1].should == SocketSpecs.port
+    addr[1].should be_kind_of(Fixnum)
     addr[2].should == '0.0.0.0'
     addr[3].should == '0.0.0.0'
   end
 
   it "binds to INADDR_ANY if the hostname is empty and the port is a string" do
-    @server = TCPServer.new('', SocketSpecs.port.to_s)
+    @server = TCPServer.new('', 0)
     addr = @server.addr
     addr[0].should == 'AF_INET'
-    addr[1].should == SocketSpecs.port
+    addr[1].should be_kind_of(Fixnum)
     addr[2].should == '0.0.0.0'
     addr[3].should == '0.0.0.0'
   end
 
   it "coerces port to string, then determines port from that number or service name" do
-    t = Object.new
-    lambda { TCPServer.new(SocketSpecs.hostname, t) }.should raise_error(TypeError)
+    lambda { TCPServer.new(SocketSpecs.hostname, Object.new) }.should raise_error(TypeError)
 
-    def t.to_str; SocketSpecs.port.to_s; end
+    port = Object.new
+    port.should_receive(:to_str).and_return("0")
 
-    @server = TCPServer.new(SocketSpecs.hostname, t)
+    @server = TCPServer.new(SocketSpecs.hostname, port)
     addr = @server.addr
-    addr[1].should == SocketSpecs.port
+    addr[1].should be_kind_of(Fixnum)
 
     # TODO: This should also accept strings like 'https', but I don't know how to
     # pick such a service port that will be able to reliably bind...
   end
 
   it "raises Errno::EADDRNOTAVAIL when the adress is unknown" do
-    lambda { TCPServer.new("1.2.3.4", 4000) }.should raise_error(Errno::EADDRNOTAVAIL)
+    lambda { TCPServer.new("1.2.3.4", 0) }.should raise_error(Errno::EADDRNOTAVAIL)
   end
 
   # There is no way to make this fail-proof on all machines, because
@@ -73,15 +72,15 @@ describe "TCPServer.new" do
   quarantine! do
     it "raises a SocketError when the host is unknown" do
       lambda {
-        TCPServer.new("--notavalidname", 4000)
+        TCPServer.new("--notavalidname", 0)
       }.should raise_error(SocketError)
     end
   end
 
   it "raises Errno::EADDRINUSE when address is already in use" do
+    @server = TCPServer.new('127.0.0.1', 0)
     lambda {
-      @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
-      @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
+      @server = TCPServer.new('127.0.0.1', @server.addr[1])
     }.should raise_error(Errno::EADDRINUSE)
   end
 
@@ -89,7 +88,7 @@ describe "TCPServer.new" do
     # A known bug in AIX.  getsockopt(2) does not properly set
     # the fifth argument for SO_REUSEADDR.
     it "sets SO_REUSEADDR on the resulting server" do
-      @server = TCPServer.new('127.0.0.1', SocketSpecs.port)
+      @server = TCPServer.new('127.0.0.1', 0)
       @server.getsockopt(:SOCKET, :REUSEADDR).data.should_not == "\x00\x00\x00\x00"
       @server.getsockopt(:SOCKET, :REUSEADDR).int.should_not == 0
     end
diff --git a/spec/rubyspec/library/socket/tcpserver/output_spec.rb b/spec/rubyspec/library/socket/tcpserver/output_spec.rb
deleted file mode 100644
index b193bb83ea..0000000000
--- a/spec/rubyspec/library/socket/tcpserver/output_spec.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-require File.expand_path('../../../../spec_helper', __FILE__)
-require File.expand_path('../../fixtures/classes', __FILE__)
-
-describe "TCPServer#<<" do
-  after :each do
-    @server.close if @server
-    @socket.close if @socket
-  end
-end
diff --git a/spec/rubyspec/library/socket/tcpserver/readpartial_spec.rb b/spec/rubyspec/library/socket/tcpserver/readpartial_spec.rb
deleted file mode 100644
index 35d07a0309..0000000000
--- a/spec/rubyspec/library/socket/tcpserver/readpartial_spec.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-require File.expand_path('../../../../spec_helper', __FILE__)
-require File.expand_path('../../fixtures/classes', __FILE__)
-
-describe "TCPServer#readpartial" do
-  after :each do
-    @server.close if @server
-    @socket.close if @socket
-  end
-end
diff --git a/spec/rubyspec/library/socket/tcpserver/sysaccept_spec.rb b/spec/rubyspec/library/socket/tcpserver/sysaccept_spec.rb
index 1cd1c1c719..93c1ffe152 100644
--- a/spec/rubyspec/library/socket/tcpserver/sysaccept_spec.rb
+++ b/spec/rubyspec/library/socket/tcpserver/sysaccept_spec.rb
@@ -5,7 +5,8 @@ require 'socket'
 
 describe "TCPServer#sysaccept" do
   before :each do
-    @server = TCPServer.new(SocketSpecs.hostname, SocketSpecs.port)
+    @server = TCPServer.new(SocketSpecs.hostname, 0)
+    @port = @server.addr[1]
   end
 
   after :each do
@@ -18,7 +19,7 @@ describe "TCPServer#sysaccept" do
 
   it 'returns file descriptor of an accepted connection' do
     begin
-      sock = TCPSocket.new(SocketSpecs.hostname, SocketSpecs.port)
+      sock = TCPSocket.new(SocketSpecs.hostname, @port)
 
       fd = @server.sysaccept
 
diff --git a/spec/rubyspec/library/socket/tcpsocket/partially_closable_spec.rb b/spec/rubyspec/library/socket/tcpsocket/partially_closable_spec.rb
index f38b251090..6a43eea625 100644
--- a/spec/rubyspec/library/socket/tcpsocket/partially_closable_spec.rb
+++ b/spec/rubyspec/library/socket/tcpsocket/partially_closable_spec.rb
@@ -5,9 +5,8 @@ require File.expand_path('../../shared/partially_closable_sockets', __FILE__)
 describe "TCPSocket partial closability" do
 
   before :each do
-    port = SocketSpecs.find_available_port
-    @server = TCPServer.new("127.0.0.1", port)
-    @s1 = TCPSocket.new("127.0.0.1", port)
+    @server = TCPServer.new("127.0.0.1", 0)
+    @s1 = TCPSocket.new("127.0.0.1", @server.addr[1])
     @s2 = @server.accept
   end
 
diff --git a/spec/rubyspec/library/socket/tcpsocket/shared/new.rb b/spec/rubyspec/library/socket/tcpsocket/shared/new.rb
index 14b6e4373b..912208c86c 100644
--- a/spec/rubyspec/library/socket/tcpsocket/shared/new.rb
+++ b/spec/rubyspec/library/socket/tcpsocket/shared/new.rb
@@ -44,8 +44,14 @@ describe :tcpsocket_new, shared: true do
     end
 
     it "connects to a server when passed local_host and local_port arguments" do
+      server = TCPServer.new(SocketSpecs.hostname, 0)
+      begin
+        available_port = server.addr[1]
+      ensure
+        server.close
+      end
       @socket = TCPSocket.send(@method, @hostname, @server.port,
-                               @hostname, SocketSpecs.local_port)
+                               @hostname, available_port)
       @socket.should be_an_instance_of(TCPSocket)
     end
 
diff --git a/spec/rubyspec/library/socket/udpsocket/bind_spec.rb b/spec/rubyspec/library/socket/udpsocket/bind_spec.rb
index 067baa2472..bdc3c3d33f 100644
--- a/spec/rubyspec/library/socket/udpsocket/bind_spec.rb
+++ b/spec/rubyspec/library/socket/udpsocket/bind_spec.rb
@@ -12,24 +12,31 @@ describe "UDPSocket.bind" do
   end
 
   it "binds the socket to a port" do
-    @socket.bind(SocketSpecs.hostname, SocketSpecs.port)
+    @socket.bind(SocketSpecs.hostname, 0)
+    @socket.addr[1].should be_kind_of(Integer)
+  end
+
+  it "raises Errno::EINVAL when already bound" do
+    @socket.bind(SocketSpecs.hostname, 0)
 
-    lambda { @socket.bind(SocketSpecs.hostname, SocketSpecs.port) }.should raise_error
+    lambda {
+      @socket.bind(SocketSpecs.hostname, @socket.addr[1])
+    }.should raise_error(Errno::EINVAL)
   end
 
   it "receives a hostname and a port" do
-    @socket.bind(SocketSpecs.hostname, SocketSpecs.port)
+    @socket.bind(SocketSpecs.hostname, 0)
 
     port, host = Socket.unpack_sockaddr_in(@socket.getsockname)
 
     host.should == "127.0.0.1"
-    port.should == SocketSpecs.port
+    port.should == @socket.addr[1]
   end
 
   it "binds to INADDR_ANY if the hostname is empty" do
-    @socket.bind("", SocketSpecs.port)
+    @socket.bind("", 0)
     port, host = Socket.unpack_sockaddr_in(@socket.getsockname)
     host.should == "0.0.0.0"
-    port.should == SocketSpecs.port
+    port.should == @socket.addr[1]
   end
 end
diff --git a/spec/rubyspec/library/socket/udpsocket/connect_spec.rb b/spec/rubyspec/library/socket/udpsocket/connect_spec.rb
deleted file mode 100644
index fcd29e1257..0000000000
--- a/spec/rubyspec/library/socket/udpsocket/connect_spec.rb
+++ /dev/null
@@ -1,2 +0,0 @@
-require File.expand_path('../../../../spec_helper', __FILE__)
-require File.expand_path('../../fixtures/classes', __FILE__)
diff --git a/spec/rubyspec/library/socket/udpsocket/recvfrom_nonblock_spec.rb b/spec/rubyspec/library/socket/udpsocket/recvfrom_nonblock_spec.rb
deleted file mode 100644
index fcd29e1257..0000000000
--- a/spec/rubyspec/library/socket/udpsocket/recvfrom_nonblock_spec.rb
+++ /dev/null
@@ -1,2 +0,0 @@
-require File.expand_path('../../../../spec_helper', __FILE__)
-require File.expand_path('../../fixtures/classes', __FILE__)
diff --git a/spec/rubyspec/library/socket/udpsocket/send_spec.rb b/spec/rubyspec/library/socket/udpsocket/send_spec.rb
index feff020dd7..1a6f44b26e 100644
--- a/spec/rubyspec/library/socket/udpsocket/send_spec.rb
+++ b/spec/rubyspec/library/socket/udpsocket/send_spec.rb
@@ -3,12 +3,12 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 
 describe "UDPSocket.send" do
   before :each do
-    @ready = false
+    @port = nil
     @server_thread = Thread.new do
       @server = UDPSocket.open
       begin
-        @server.bind(nil, SocketSpecs.port)
-        @ready = true
+        @server.bind(nil, 0)
+        @port = @server.addr[1]
         begin
           @msg = @server.recvfrom_nonblock(64)
         rescue IO::WaitReadable
@@ -19,12 +19,16 @@ describe "UDPSocket.send" do
         @server.close if !@server.closed?
       end
     end
-    Thread.pass while @server_thread.status and !@ready
+    Thread.pass while @server_thread.status and !@port
+  end
+
+  after :each do
+    @server_thread.join
   end
 
   it "sends data in ad hoc mode" do
     @socket = UDPSocket.open
-    @socket.send("ad hoc", 0, SocketSpecs.hostname, SocketSpecs.port)
+    @socket.send("ad hoc", 0, SocketSpecs.hostname, @port)
     @socket.close
     @server_thread.join
 
@@ -36,7 +40,7 @@ describe "UDPSocket.send" do
 
   it "sends data in ad hoc mode (with port given as a String)" do
     @socket = UDPSocket.open
-    @socket.send("ad hoc", 0, SocketSpecs.hostname, SocketSpecs.str_port)
+    @socket.send("ad hoc", 0, SocketSpecs.hostname, @port.to_s)
     @socket.close
     @server_thread.join
 
@@ -48,7 +52,7 @@ describe "UDPSocket.send" do
 
   it "sends data in connection mode" do
     @socket = UDPSocket.open
-    @socket.connect(SocketSpecs.hostname, SocketSpecs.port)
+    @socket.connect(SocketSpecs.hostname, @port)
     @socket.send("connection-based", 0)
     @socket.close
     @server_thread.join
@@ -63,10 +67,10 @@ describe "UDPSocket.send" do
     @socket = UDPSocket.open
     begin
       lambda do
-        @socket.send('1' * 100_000, 0, SocketSpecs.hostname, SocketSpecs.str_port)
+        @socket.send('1' * 100_000, 0, SocketSpecs.hostname, @port.to_s)
       end.should raise_error(Errno::EMSGSIZE)
     ensure
-      @socket.send("ad hoc", 0, SocketSpecs.hostname, SocketSpecs.port)
+      @socket.send("ad hoc", 0, SocketSpecs.hostname, @port)
       @socket.close
       @server_thread.join
     end
diff --git a/spec/rubyspec/library/socket/udpsocket/write_spec.rb b/spec/rubyspec/library/socket/udpsocket/write_spec.rb
index 97985ff7ae..11e38bb470 100644
--- a/spec/rubyspec/library/socket/udpsocket/write_spec.rb
+++ b/spec/rubyspec/library/socket/udpsocket/write_spec.rb
@@ -4,11 +4,11 @@ require File.expand_path('../../fixtures/classes', __FILE__)
 describe "UDPSocket#write" do
   it "raises EMSGSIZE if msg is too long" do
     begin
-      host, port = SocketSpecs.hostname, SocketSpecs.port
+      host = SocketSpecs.hostname
       s1 = UDPSocket.new
-      s1.bind(host, port)
+      s1.bind(host, 0)
       s2 = UDPSocket.new
-      s2.connect(host, port)
+      s2.connect(host, s1.addr[1])
 
       lambda do
         s2.write('1' * 100_000)
diff --git a/spec/rubyspec/library/socket/unixserver/accept_spec.rb b/spec/rubyspec/library/socket/unixserver/accept_spec.rb
index 15459f5043..90b22d7eb1 100644
--- a/spec/rubyspec/library/socket/unixserver/accept_spec.rb
+++ b/spec/rubyspec/library/socket/unixserver/accept_spec.rb
@@ -5,53 +5,50 @@ platform_is_not :windows do
   describe "UNIXServer#accept" do
     before :each do
       @path = SocketSpecs.socket_path
+      @server = UNIXServer.open(@path)
     end
 
     after :each do
+      @server.close if @server
       SocketSpecs.rm_socket @path
     end
 
     it "accepts what is written by the client" do
-      server = UNIXServer.open(@path)
       client = UNIXSocket.open(@path)
 
       client.send('hello', 0)
 
-      sock = server.accept
-      data, info = sock.recvfrom(5)
+      sock = @server.accept
+      begin
+        data, info = sock.recvfrom(5)
 
-      data.should == 'hello'
-      info.should_not be_empty
-
-      server.close
-      client.close
-      sock.close
+        data.should == 'hello'
+        info.should_not be_empty
+      ensure
+        sock.close
+        client.close
+      end
     end
 
     it "can be interrupted by Thread#kill" do
-      server = UNIXServer.new(@path)
       t = Thread.new {
-        server.accept
+        @server.accept
       }
       Thread.pass while t.status and t.status != "sleep"
 
       # kill thread, ensure it dies in a reasonable amount of time
       t.kill
-      a = 1
-      while a < 2000
-        break unless t.alive?
-        Thread.pass
-        sleep 0.2
+      a = 0
+      while t.alive? and a < 5000
+        sleep 0.001
         a += 1
       end
-      a.should < 2000
-      server.close
+      a.should < 5000
     end
 
     it "can be interrupted by Thread#raise" do
-      server = UNIXServer.new(@path)
       t = Thread.new {
-        server.accept
+        @server.accept
       }
       Thread.pass while t.status and t.status != "sleep"
 
@@ -59,7 +56,6 @@ platform_is_not :windows do
       ex = Exception.new
       t.raise ex
       lambda { t.join }.should raise_error(Exception)
-      server.close
     end
   end
 end
diff --git a/spec/rubyspec/optional/capi/ext/jruby.h b/spec/rubyspec/optional/capi/ext/jruby.h
deleted file mode 100644
index 00a9789f14..0000000000
--- a/spec/rubyspec/optional/capi/ext/jruby.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef RUBYSPEC_CAPI_JRUBY_H
-#define RUBYSPEC_CAPI_JRUBY_H
-
-/* #undef any HAVE_ defines that JRuby does not have. */
-#undef HAVE_RB_DEFINE_HOOKED_VARIABLE
-#undef HAVE_RB_DEFINE_VARIABLE
-
-#undef HAVE_RB_EXEC_RECURSIVE
-
-#endif
diff --git a/spec/rubyspec/optional/capi/ext/rubinius.h b/spec/rubyspec/optional/capi/ext/rubinius.h
deleted file mode 100644
index 7ddf73790d..0000000000
--- a/spec/rubyspec/optional/capi/ext/rubinius.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef RUBYSPEC_CAPI_RUBINIUS_H
-#define RUBYSPEC_CAPI_RUBINIUS_H
-
-/* #undef any HAVE_ defines that Rubinius does not have. */
-#undef HAVE_RB_DEFINE_HOOKED_VARIABLE
-#undef HAVE_RB_DEFINE_VARIABLE
-
-#endif
diff --git a/spec/rubyspec/optional/capi/ext/rubyspec.h b/spec/rubyspec/optional/capi/ext/rubyspec.h
index aa0f4def19..9cba34b888 100644
--- a/spec/rubyspec/optional/capi/ext/rubyspec.h
+++ b/spec/rubyspec/optional/capi/ext/rubyspec.h
@@ -595,19 +595,4 @@
 /* Util */
 #define HAVE_RB_SCAN_ARGS                  1
 
-/* Now, create the differential set. The format of the preprocessor directives
- * is significant. The alternative implementations should define RUBY because
- * some extensions depend on that. But only one alternative implementation
- * macro should be defined at a time. The conditional is structured so that if
- * no alternative implementation is defined then MRI is assumed.
- */
-
-#if defined(RUBINIUS)
-#include "rubinius.h"
-#elif defined(JRUBY)
-#include "jruby.h"
-#elif defined(TRUFFLERUBY)
-#include "truffleruby.h"
-#endif
-
 #endif
diff --git a/spec/rubyspec/optional/capi/ext/truffleruby.h b/spec/rubyspec/optional/capi/ext/truffleruby.h
deleted file mode 100644
index 99976a18a4..0000000000
--- a/spec/rubyspec/optional/capi/ext/truffleruby.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef RUBYSPEC_CAPI_TRUFFLERUBY_H
-#undef RUBYSPEC_CAPI_TRUFFLERUBY_H
-
-// All features are available
-
-#endif
diff --git a/spec/rubyspec/optional/capi/module_spec.rb b/spec/rubyspec/optional/capi/module_spec.rb
index 1c21ad2e7c..23fb674f0e 100644
--- a/spec/rubyspec/optional/capi/module_spec.rb
+++ b/spec/rubyspec/optional/capi/module_spec.rb
@@ -62,16 +62,18 @@ describe "CApiModule" do
       mod = @m.rb_define_module_under(CApiModuleSpecs, "ModuleSpecsModuleUnder2")
       mod.name.should == "CApiModuleSpecs::ModuleSpecsModuleUnder2"
     end
+  end
 
-    it "defines a module for an existing Autoload with an extension" do
+  describe "rb_define_module_under" do
+    before :each do
       compile_extension("module_under_autoload")
+    end
 
+    it "defines a module for an existing Autoload with an extension" do
       CApiModuleSpecs::ModuleUnderAutoload.name.should == "CApiModuleSpecs::ModuleUnderAutoload"
     end
 
     it "defines a module for an existing Autoload with a ruby object" do
-      compile_extension("module_under_autoload")
-
       CApiModuleSpecs::RubyUnderAutoload.name.should == "CApiModuleSpecs::RubyUnderAutoload"
     end
   end
diff --git a/spec/rubyspec/optional/capi/spec_helper.rb b/spec/rubyspec/optional/capi/spec_helper.rb
index 2a0c515306..71b765de07 100644
--- a/spec/rubyspec/optional/capi/spec_helper.rb
+++ b/spec/rubyspec/optional/capi/spec_helper.rb
@@ -1,9 +1,11 @@
 require File.expand_path('../../../spec_helper', __FILE__)
+
+# MRI magic to use built but not installed ruby
 $extmk = false
 
 require 'rbconfig'
 
-OBJDIR ||= File.expand_path("../../../ext/#{RUBY_NAME}/#{RUBY_VERSION}", __FILE__)
+OBJDIR ||= File.expand_path("../../../ext/#{RUBY_ENGINE}/#{RUBY_VERSION}", __FILE__)
 mkdir_p(OBJDIR)
 
 def extension_path
@@ -15,130 +17,59 @@ def object_path
 end
 
 def compile_extension(name)
-  preloadenv = RbConfig::CONFIG["PRELOADENV"] || "LD_PRELOAD"
-  preload, ENV[preloadenv] = ENV[preloadenv], nil if preloadenv
-
-  path = extension_path
-  objdir = object_path
-
-  # TODO use rakelib/ext_helper.rb?
-  arch_hdrdir = nil
-
-  if RUBY_NAME == 'rbx'
-    hdrdir = RbConfig::CONFIG["rubyhdrdir"]
-  elsif RUBY_NAME =~ /^ruby/
-    hdrdir = RbConfig::CONFIG["rubyhdrdir"]
-    arch_hdrdir = RbConfig::CONFIG["rubyarchhdrdir"]
-  elsif RUBY_NAME == 'jruby'
-    require 'mkmf'
-    hdrdir = $hdrdir
-  elsif RUBY_NAME == "maglev"
-    require 'mkmf'
-    hdrdir = $hdrdir
-  elsif RUBY_NAME == 'truffleruby'
-    return compile_truffleruby_extconf_make(name, path, objdir)
-  else
-    raise "Don't know how to build C extensions with #{RUBY_NAME}"
-  end
-
-  ext       = "#{name}_spec"
-  source    = File.join(path, "#{ext}.c")
-  obj       = File.join(objdir, "#{ext}.#{RbConfig::CONFIG['OBJEXT']}")
-  lib       = File.join(objdir, "#{ext}.#{RbConfig::CONFIG['DLEXT']}")
+  debug = false
+  run_mkmf_in_process = RUBY_ENGINE == 'truffleruby'
 
-  ruby_header     = File.join(hdrdir, "ruby.h")
-  rubyspec_header = File.join(path, "rubyspec.h")
+  ext = "#{name}_spec"
+  lib = "#{object_path}/#{ext}.#{RbConfig::CONFIG['DLEXT']}"
+  ruby_header = "#{RbConfig::CONFIG['rubyhdrdir']}/ruby.h"
 
-  return lib if File.exist?(lib) and File.mtime(lib) > File.mtime(source) and
+  return lib if File.exist?(lib) and
+                File.mtime(lib) > File.mtime("#{extension_path}/rubyspec.h") and
+                File.mtime(lib) > File.mtime("#{extension_path}/#{ext}.c") and
                 File.mtime(lib) > File.mtime(ruby_header) and
-                File.mtime(lib) > File.mtime(rubyspec_header) and
                 true            # sentinel
 
-  # avoid problems where compilation failed but previous shlib exists
-  File.delete lib if File.exist? lib
-
-  cc        = RbConfig::CONFIG["CC"]
-  cflags    = (ENV["CFLAGS"] || RbConfig::CONFIG["CFLAGS"]).dup
-  cflags   += " #{RbConfig::CONFIG["ARCH_FLAG"]}" if RbConfig::CONFIG["ARCH_FLAG"]
-  cflags   += " #{RbConfig::CONFIG["CCDLFLAGS"]}" if RbConfig::CONFIG["CCDLFLAGS"]
-  cppflags  = (ENV["CPPFLAGS"] || RbConfig::CONFIG["CPPFLAGS"]).dup
-  incflags  = "-I#{path}"
-  incflags << " -I#{arch_hdrdir}" if arch_hdrdir
-  incflags << " -I#{hdrdir}"
-  csrcflag  = RbConfig::CONFIG["CSRCFLAG"]
-  coutflag  = RbConfig::CONFIG["COUTFLAG"]
-
-  compile_cmd = "#{cc} #{incflags} #{cflags} #{cppflags} #{coutflag}#{obj} -c #{csrcflag}#{source}"
-  output = `#{compile_cmd}`
-
-  unless $?.success? and File.exist?(obj)
-    puts "\nERROR:\n#{compile_cmd}\n#{output}"
-    puts "incflags=#{incflags}"
-    puts "cflags=#{cflags}"
-    puts "cppflags=#{cppflags}"
-    raise "Unable to compile \"#{source}\""
-  end
-
-  ldshared  = RbConfig::CONFIG["LDSHARED"]
-  ldshared += " #{RbConfig::CONFIG["ARCH_FLAG"]}" if RbConfig::CONFIG["ARCH_FLAG"]
-  libs      = RbConfig::CONFIG["LIBS"]
-  dldflags  = "#{RbConfig::CONFIG["LDFLAGS"]} #{RbConfig::CONFIG["DLDFLAGS"]} #{RbConfig::CONFIG["EXTDLDFLAGS"]}"
-  dldflags.sub!(/-Wl,-soname,\S+/, '')
-
-  if /mswin/ =~ RUBY_PLATFORM
-    dldflags.sub!("$(LIBPATH)", RbConfig::CONFIG["LIBPATHFLAG"] % path)
-    libs    += RbConfig::CONFIG["LIBRUBY"]
-    outflag  = RbConfig::CONFIG["OUTFLAG"]
-
-    link_cmd = "#{ldshared} #{outflag}#{lib} #{obj} #{libs} -link #{dldflags} /export:Init_#{ext}"
-  else
-    libpath   = "-L#{path}"
-    dldflags.sub!("$(TARGET_ENTRY)", "Init_#{ext}")
-
-    link_cmd = "#{ldshared} #{obj} #{libpath} #{dldflags} #{libs} -o #{lib}"
-  end
-  output = `#{link_cmd}`
-
-  unless $?.success?
-    puts "\nERROR:\n#{link_cmd}\n#{output}"
-    raise "Unable to link \"#{source}\""
-  end
-
-  lib
-ensure
-  ENV[preloadenv] = preload if preloadenv
-end
-
-def compile_truffleruby_extconf_make(name, path, objdir)
-  ext = "#{name}_spec"
-  file = "#{ext}.c"
-  source = "#{path}/#{ext}.c"
-  lib = "#{objdir}/#{ext}.#{RbConfig::CONFIG['DLEXT']}"
-
   # Copy needed source files to tmpdir
   tmpdir = tmp("cext_#{name}")
-  Dir.mkdir tmpdir
+  Dir.mkdir(tmpdir)
   begin
-    ["rubyspec.h", "truffleruby.h", "#{ext}.c"].each do |file|
-      cp "#{path}/#{file}", "#{tmpdir}/#{file}"
+    ["rubyspec.h", "#{ext}.c"].each do |file|
+      cp "#{extension_path}/#{file}", "#{tmpdir}/#{file}"
     end
 
     Dir.chdir(tmpdir) do
-      required = require 'mkmf'
-      # Reinitialize mkmf if already required
-      init_mkmf unless required
-      create_makefile(ext, tmpdir)
-      system "make"
-
-      copy_exts = RbConfig::CONFIG.values_at('OBJEXT', 'DLEXT')
-      Dir.glob("*.{#{copy_exts.join(',')}}") do |file|
-        cp file, "#{objdir}/#{file}"
+      if run_mkmf_in_process
+        required = require 'mkmf'
+        # Reinitialize mkmf if already required
+        init_mkmf unless required
+        create_makefile(ext, tmpdir)
+      else
+        File.write("extconf.rb", "require 'mkmf'\n" +
+          "$ruby = ENV.values_at('RUBY_EXE', 'RUBY_FLAGS').join(' ')\n" +
+          # MRI magic to consider building non-bundled extensions
+          "$extout = nil\n" +
+          "create_makefile(#{ext.inspect})\n")
+        output = ruby_exe("extconf.rb")
+        raise "extconf failed:\n#{output}" unless $?.success?
+        $stderr.puts output if debug
       end
+
+      make = RbConfig::CONFIG['host_os'].include?("mswin") ? "nmake" : "make"
+      ENV.delete "MAKEFLAGS" # Fix make warning when invoked with -j in MRI
+
+      # Do not capture stderr as we want to show compiler warnings
+      output = `#{make} V=1`
+      raise "#{make} failed:\n#{output}" unless $?.success?
+      $stderr.puts output if debug
+
+      cp File.basename(lib), lib
     end
   ensure
     rm_r tmpdir
   end
 
+  File.chmod(0755, lib)
   lib
 end
 
diff --git a/spec/rubyspec/optional/capi/string_spec.rb b/spec/rubyspec/optional/capi/string_spec.rb
index ce0485e8af..7528a71682 100644
--- a/spec/rubyspec/optional/capi/string_spec.rb
+++ b/spec/rubyspec/optional/capi/string_spec.rb
@@ -501,7 +501,7 @@ describe "C-API String function" do
   describe "rb_str_hash" do
     it "hashes the string into a number" do
       s = "hello"
-      @s.rb_str_hash(s).should == s.hash
+      @s.rb_str_hash(s).should be_kind_of(Integer)
     end
   end
 
diff --git a/spec/rubyspec/optional/capi/time_spec.rb b/spec/rubyspec/optional/capi/time_spec.rb
index 98b609e83e..c8f0d9d4e0 100644
--- a/spec/rubyspec/optional/capi/time_spec.rb
+++ b/spec/rubyspec/optional/capi/time_spec.rb
@@ -165,28 +165,30 @@ describe "CApiTimeSpecs" do
       usec.should == 500000
     end
 
-    it "creates a timeval for a negative Fixnum" do
-      sec, usec = @s.rb_time_timeval(-1232141421)
-      sec.should be_kind_of(Integer)
-      sec.should == -1232141421
-      usec.should be_kind_of(Integer)
-      usec.should == 0
-    end
+    platform_is_not :mingw32 do
+      it "creates a timeval for a negative Fixnum" do
+        sec, usec = @s.rb_time_timeval(-1232141421)
+        sec.should be_kind_of(Integer)
+        sec.should == -1232141421
+        usec.should be_kind_of(Integer)
+        usec.should == 0
+      end
 
-    it "creates a timeval for a negative Float" do
-      sec, usec = @s.rb_time_timeval(-1.5)
-      sec.should be_kind_of(Integer)
-      sec.should == -2
-      usec.should be_kind_of(Integer)
-      usec.should == 500000
-    end
+      it "creates a timeval for a negative Float" do
+        sec, usec = @s.rb_time_timeval(-1.5)
+        sec.should be_kind_of(Integer)
+        sec.should == -2
+        usec.should be_kind_of(Integer)
+        usec.should == 500000
+      end
 
-    it "creates a timeval for a negative Rational" do
-      sec, usec = @s.rb_time_timeval(Rational(-3, 2))
-      sec.should be_kind_of(Integer)
-      sec.should == -2
-      usec.should be_kind_of(Integer)
-      usec.should == 500000
+      it "creates a timeval for a negative Rational" do
+        sec, usec = @s.rb_time_timeval(Rational(-3, 2))
+        sec.should be_kind_of(Integer)
+        sec.should == -2
+        usec.should be_kind_of(Integer)
+        usec.should == 500000
+      end
     end
 
     it "creates a timeval from a Time object" do
@@ -222,28 +224,30 @@ describe "CApiTimeSpecs" do
       nsec.should == 500000000
     end
 
-    it "creates a timespec for a negative Fixnum" do
-      sec, nsec = @s.rb_time_timespec(-1232141421)
-      sec.should be_kind_of(Integer)
-      sec.should == -1232141421
-      nsec.should be_kind_of(Integer)
-      nsec.should == 0
-    end
+    platform_is_not :mingw32 do
+      it "creates a timespec for a negative Fixnum" do
+        sec, nsec = @s.rb_time_timespec(-1232141421)
+        sec.should be_kind_of(Integer)
+        sec.should == -1232141421
+        nsec.should be_kind_of(Integer)
+        nsec.should == 0
+      end
 
-    it "creates a timespec for a negative Float" do
-      sec, nsec = @s.rb_time_timespec(-1.5)
-      sec.should be_kind_of(Integer)
-      sec.should == -2
-      nsec.should be_kind_of(Integer)
-      nsec.should == 500000000
-    end
+      it "creates a timespec for a negative Float" do
+        sec, nsec = @s.rb_time_timespec(-1.5)
+        sec.should be_kind_of(Integer)
+        sec.should == -2
+        nsec.should be_kind_of(Integer)
+        nsec.should == 500000000
+      end
 
-    it "creates a timespec for a negative Rational" do
-      sec, nsec = @s.rb_time_timespec(Rational(-3, 2))
-      sec.should be_kind_of(Integer)
-      sec.should == -2
-      nsec.should be_kind_of(Integer)
-      nsec.should == 500000000
+      it "creates a timespec for a negative Rational" do
+        sec, nsec = @s.rb_time_timespec(Rational(-3, 2))
+        sec.should be_kind_of(Integer)
+        sec.should == -2
+        nsec.should be_kind_of(Integer)
+        nsec.should == 500000000
+      end
     end
 
     it "creates a timespec from a Time object" do