Surface Windows build errors in non-verbose mode (#63707)

packages/flutter_tools/lib/src/base/process.dart

@@ -257,6 +257,9 @@ abstract class ProcessUtils {
   /// If [filter] is non-null, all lines that do not match it are removed. If
   /// [mapFunction] is present, all lines that match [filter] are also forwarded
   /// to [mapFunction] for further processing.
+  ///
+  /// If [stdoutErrorMatcher] is non-null, matching lines from stdout will be
+  /// treated as errors, just as if they had been logged to stderr instead.
   Future<int> stream(
     List<String> cmd, {
     String workingDirectory,
@@ -264,6 +267,7 @@ abstract class ProcessUtils {
     String prefix = '',
     bool trace = false,
     RegExp filter,
+    RegExp stdoutErrorMatcher,
     StringConverter mapFunction,
     Map<String, String> environment,
   });
@@ -485,6 +489,7 @@ class _DefaultProcessUtils implements ProcessUtils {
     String prefix = '',
     bool trace = false,
     RegExp filter,
+    RegExp stdoutErrorMatcher,
     StringConverter mapFunction,
     Map<String, String> environment,
   }) async {
@@ -504,7 +509,9 @@ class _DefaultProcessUtils implements ProcessUtils {
         }
         if (line != null) {
           final String message = '$prefix$line';
-          if (trace) {
+          if (stdoutErrorMatcher?.hasMatch(line) == true) {
+            _logger.printError(message, wrap: false);
+          } else if (trace) {
             _logger.printTrace(message);
           } else {
             _logger.printStatus(message, wrap: false);

packages/flutter_tools/lib/src/windows/build_windows.dart

@@ -107,6 +107,10 @@ Future<void> _runCmakeGeneration(String cmakePath, Directory buildDir, Directory
 Future<void> _runBuild(String cmakePath, Directory buildDir, String buildModeName) async {
   final Stopwatch sw = Stopwatch()..start();
 
+  // MSBuild sends all output to stdout, including build errors. This surfaces
+  // known error patterns.
+  final RegExp errorMatcher = RegExp(r':\s*(?:warning|(?:fatal )?error).*?:');
+
   int result;
   try {
     result = await processUtils.stream(
@@ -126,13 +130,13 @@ Future<void> _runBuild(String cmakePath, Directory buildDir, String buildModeNam
           'VERBOSE_SCRIPT_LOGGING': 'true'
       },
       trace: true,
+      stdoutErrorMatcher: errorMatcher,
     );
   } on ArgumentError {
     throwToolExit("cmake not found. Run 'flutter doctor' for more information.");
   }
   if (result != 0) {
-    final String verboseInstructions = globals.logger.isVerbose ? '' : ' To view the stack trace, please run `flutter run -d windows -v`.';
+    throwToolExit('Build process failed.');
-    throwToolExit('Build process failed.$verboseInstructions');
   }
   globals.flutterUsage.sendTiming('build', 'windows-cmake-build', Duration(milliseconds: sw.elapsedMilliseconds));
 }

packages/flutter_tools/templates/app/windows.tmpl/flutter/CMakeLists.txt

@@ -80,11 +80,13 @@ add_dependencies(flutter_wrapper_app flutter_assemble)
 # _phony_ is a non-existent file to force this command to run every time,
 # since currently there's no way to get a full input/output list from the
 # flutter tool.
+set(PHONY_OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/_phony_")
+set_source_files_properties("${PHONY_OUTPUT}" PROPERTIES SYMBOLIC TRUE)
 add_custom_command(
   OUTPUT ${FLUTTER_LIBRARY} ${FLUTTER_LIBRARY_HEADERS}
     ${CPP_WRAPPER_SOURCES_CORE} ${CPP_WRAPPER_SOURCES_PLUGIN}
     ${CPP_WRAPPER_SOURCES_APP}
-    ${CMAKE_CURRENT_BINARY_DIR}/_phony_
+    ${PHONY_OUTPUT}
   COMMAND ${CMAKE_COMMAND} -E env
     ${FLUTTER_TOOL_ENVIRONMENT}
     "${FLUTTER_ROOT}/packages/flutter_tools/bin/tool_backend.bat"

packages/flutter_tools/test/commands.shard/hermetic/build_windows_test.dart

@@ -239,6 +239,63 @@ void main() {
     FeatureFlags: () => TestFeatureFlags(isWindowsEnabled: true),
   });
 
+  testUsingContext('Windows build extracts errors from stdout', () async {
+    final BuildWindowsCommand command = BuildWindowsCommand()
+      ..visualStudioOverride = mockVisualStudio;
+    applyMocksToCommand(command);
+    setUpMockProjectFilesForBuild();
+    when(mockVisualStudio.cmakePath).thenReturn(cmakePath);
+
+    // This contains a mix of routine build output and various types of errors
+    // (compile error, link error, warning treated as an error) from MSBuild,
+    // edited down for compactness. For instance, where similar lines are
+    // repeated in actual output, one or two representative lines are chosen
+    // to be included here.
+    const String stdout = r'''Microsoft (R) Build Engine version 16.6.0+5ff7b0c9e for .NET Framework
+Copyright (C) Microsoft Corporation. All rights reserved.
+
+  Checking Build System
+  Generating C:/foo/windows/flutter/ephemeral/flutter_windows.dll, [etc], _phony_
+  Building Custom Rule C:/foo/windows/flutter/CMakeLists.txt
+  standard_codec.cc
+  Generating Code...
+  flutter_wrapper_plugin.vcxproj -> C:\foo\build\windows\flutter\Debug\flutter_wrapper_plugin.lib
+C:\foo\windows\runner\main.cpp(18): error C2220: the following warning is treated as an error [C:\foo\build\windows\runner\test.vcxproj]
+C:\foo\windows\runner\main.cpp(18): warning C4706: assignment within conditional expression [C:\foo\build\windows\runner\test.vcxproj]
+main.obj : error LNK2019: unresolved external symbol "void __cdecl Bar(void)" (?Bar@@YAXXZ) referenced in function wWinMain [C:\foo\build\windows\runner\test.vcxproj]
+C:\foo\build\windows\runner\Debug\test.exe : fatal error LNK1120: 1 unresolved externals [C:\foo\build\windows\runner\test.vcxproj]
+  Building Custom Rule C:/foo/windows/runner/CMakeLists.txt
+  flutter_window.cpp
+  main.cpp
+C:\foo\windows\runner\main.cpp(17,1): error C2065: 'Baz': undeclared identifier [C:\foo\build\windows\runner\test.vcxproj]
+  -- Install configuration: "Debug"
+  -- Installing: C:/foo/build/windows/runner/Debug/data/icudtl.dat
+''';
+
+    processManager = FakeProcessManager.list(<FakeCommand>[
+      cmakeGenerationCommand(),
+      buildCommand('Release',
+        stdout: stdout,
+      ),
+    ]);
+
+    await createTestCommandRunner(command).run(
+      const <String>['windows', '--no-pub']
+    );
+    // Just the warnings and errors should be surfaced.
+    expect(testLogger.errorText, r'''C:\foo\windows\runner\main.cpp(18): error C2220: the following warning is treated as an error [C:\foo\build\windows\runner\test.vcxproj]
+C:\foo\windows\runner\main.cpp(18): warning C4706: assignment within conditional expression [C:\foo\build\windows\runner\test.vcxproj]
+main.obj : error LNK2019: unresolved external symbol "void __cdecl Bar(void)" (?Bar@@YAXXZ) referenced in function wWinMain [C:\foo\build\windows\runner\test.vcxproj]
+C:\foo\build\windows\runner\Debug\test.exe : fatal error LNK1120: 1 unresolved externals [C:\foo\build\windows\runner\test.vcxproj]
+C:\foo\windows\runner\main.cpp(17,1): error C2065: 'Baz': undeclared identifier [C:\foo\build\windows\runner\test.vcxproj]
+''');
+  }, overrides: <Type, Generator>{
+    FileSystem: () => fileSystem,
+    ProcessManager: () => processManager,
+    Platform: () => windowsPlatform,
+    FeatureFlags: () => TestFeatureFlags(isWindowsEnabled: true),
+  });
+
   testUsingContext('Windows verbose build sets VERBOSE_SCRIPT_LOGGING', () async {
     final BuildWindowsCommand command = BuildWindowsCommand()
       ..visualStudioOverride = mockVisualStudio;