Add the feature flag that allows users to opt out automatic UTF8 console encoding

documentation/wiki/MSBuild-Environment-Variables.md

@@ -34,3 +34,5 @@ Some of the env variables listed here are unsupported, meaning there is no guara
   - Set this to force all tasks to run out of process (except inline tasks).
 - `MSBUILDFORCEINLINETASKFACTORIESOUTOFPROC`
   - Set this to force all inline tasks to run out of process. It is not compatible with custom TaskFactories.
+- `CONSOLE_USE_DEFAULT_ENCODING`
+  - It opts out automatic console encoding UTF-8. Make Console use default encoding in the system.

src/Framework/Traits.cs

@@ -147,6 +147,11 @@ public Traits()
         /// </summary>
         public readonly bool ForceTaskFactoryOutOfProc = Environment.GetEnvironmentVariable("MSBUILDFORCEINLINETASKFACTORIESOUTOFPROC") == "1";
 
+        /// <summary>
+        /// Make Console use default encoding in the system. It opts out automatic console encoding UTF-8.
+        /// </summary>
+        public readonly bool ConsoleUseDefaultEncoding = Environment.GetEnvironmentVariable("CONSOLE_USE_DEFAULT_ENCODING") == "1";
+
         /// <summary>
         /// Variables controlling opt out at the level of not initializing telemetry infrastructure. Set to "1" or "true" to opt out.
         /// mirroring

src/MSBuild/XMake.cs

@@ -1934,23 +1934,26 @@ internal static void SetConsoleUI()
             CultureInfo.CurrentUICulture = desiredCulture;
             CultureInfo.DefaultThreadCurrentUICulture = desiredCulture;
 
+            if (!Traits.Instance.ConsoleUseDefaultEncoding)
+            {
 #if RUNTIME_TYPE_NETCORE
-            if (EncodingUtilities.CurrentPlatformIsWindowsAndOfficiallySupportsUTF8Encoding())
+                if (EncodingUtilities.CurrentPlatformIsWindowsAndOfficiallySupportsUTF8Encoding())
 #else
-            if (EncodingUtilities.CurrentPlatformIsWindowsAndOfficiallySupportsUTF8Encoding()
-                && !CultureInfo.CurrentUICulture.TwoLetterISOLanguageName.Equals("en", StringComparison.InvariantCultureIgnoreCase))
+                if (EncodingUtilities.CurrentPlatformIsWindowsAndOfficiallySupportsUTF8Encoding()
+                    && !CultureInfo.CurrentUICulture.TwoLetterISOLanguageName.Equals("en", StringComparison.InvariantCultureIgnoreCase))
 #endif
-            {
-                try
-                {
-                    // Setting both encodings causes a change in the CHCP, making it so we don't need to P-Invoke CHCP ourselves.
-                    Console.OutputEncoding = Encoding.UTF8;
-                    // If the InputEncoding is not set, the encoding will work in CMD but not in PowerShell, as the raw CHCP page won't be changed.
-                    Console.InputEncoding = Encoding.UTF8;
-                }
-                catch (Exception ex) when (ex is IOException || ex is SecurityException)
                 {
-                    // The encoding is unavailable. Do nothing.
+                    try
+                    {
+                        // Setting both encodings causes a change in the CHCP, making it so we don't need to P-Invoke CHCP ourselves.
+                        Console.OutputEncoding = Encoding.UTF8;
+                        // If the InputEncoding is not set, the encoding will work in CMD but not in PowerShell, as the raw CHCP page won't be changed.
+                        Console.InputEncoding = Encoding.UTF8;
+                    }
+                    catch (Exception ex) when (ex is IOException || ex is SecurityException)
+                    {
+                        // The encoding is unavailable. Do nothing.
+                    }
                 }
             }