Cygwin doesn't work well if we try to capture stderr and stdout at the same time. Comment one test tempraly for Cygwin. Need to figure out why and add the test back for Cygwin.

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -85,7 +85,7 @@ class CommandLineInterfaceTest : public testing::Test {
   // Runs the CommandLineInterface with the given command line.  The
   // command is automatically split on spaces, and the string "$tmpdir"
   // is replaced with TestTempDir().
-  void Run(const string& command, bool capture_stdout = false);
+  void Run(const string& command);
 
   // -----------------------------------------------------------------
   // Methods to set up the test (called before Run()).
@@ -261,7 +261,7 @@ void CommandLineInterfaceTest::TearDown() {
   mock_generators_to_delete_.clear();
 }
 
-void CommandLineInterfaceTest::Run(const string& command, bool capture_stdout) {
+void CommandLineInterfaceTest::Run(const string& command) {
   vector<string> args = Split(command, " ", true);
 
   if (!disallow_plugins_) {
@@ -308,17 +308,20 @@ void CommandLineInterfaceTest::Run(const string& command, bool capture_stdout) {
     argv[i] = args[i].c_str();
   }
 
-  if (capture_stdout) {
-    CaptureTestStdout();
-  }
+  // TODO(jieluo): Cygwin doesn't work well if we try to capture stderr and
+  // stdout at the same time. Need to figure out why and add this capture back
+  // for Cygwin.
+#if !defined(__CYGWIN__)
+  CaptureTestStdout();
+#endif
   CaptureTestStderr();
 
   return_code_ = cli_.Run(args.size(), argv.get());
 
   error_text_ = GetCapturedTestStderr();
-  if (capture_stdout) {
-    captured_stdout_ = GetCapturedTestStdout();
-  }
+#if !defined(__CYGWIN__)
+  captured_stdout_ = GetCapturedTestStdout();
+#endif
 }
 
 // -------------------------------------------------------------------
@@ -1465,9 +1468,14 @@ TEST_F(CommandLineInterfaceTest, PrintFreeFieldNumbers) {
       "}\n");
 
   Run("protocol_compiler --print_free_field_numbers --proto_path=$tmpdir "
-      "foo.proto bar.proto baz.proto quz.proto", true);
+      "foo.proto bar.proto baz.proto quz.proto");
 
   ExpectNoErrors();
+
+  // TODO(jieluo): Cygwin doesn't work well if we try to capture stderr and
+  // stdout at the same time. Need to figure out why and add this test back
+  // for Cygwin.
+#if !defined(__CYGWIN__)
   ExpectCapturedStdout(
       "foo.Foo                             free: 1 3 6-7 9 11-INF\n"
       "Bar                                 free: 1 3 6-7 9 11-INF\n"
@@ -1475,6 +1483,7 @@ TEST_F(CommandLineInterfaceTest, PrintFreeFieldNumbers) {
       "Quz.Foo                             free: 1-INF\n"
       "Quz.E.G.Foo                         free: 1-INF\n"
       "Quz                                 free: 1 3 6-7 12-14 16-INF\n");
+#endif
 }
 
 // ===================================================================