Only enable Aspire functionality in non-optimized builds (i.e. Debug)

src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.targets

@@ -84,6 +84,16 @@
 			Condition="'$(_XFTargetsImported)' == 'true'"/>
 	</Target>
 
+	<Target
+		Name="_ValidateMauiAspireProperty"
+		BeforeTargets="_CheckForInvalidConfigurationAndPlatform"
+		Condition="'$(MauiDisableAspireValidation)' != 'True'">
+		<Warning
+			Code="MA002"
+			Text="The _EnableMauiAspire property should not be set manually. Using Aspire outside the Debug configuration may introduce performance and security risks in production. This property is automatically configured based on build configuration."
+			Condition="'$(_EnableMauiAspire)' != '' and '$(_MauiAspireSetByTargets)' != 'true'"/>
+	</Target>
+
   <Target Name="_MauiXamlComputeInflator">
   	<ItemGroup>
       <!-- Assign the default inflator to MauiXaml that don't have any -->
@@ -280,6 +290,9 @@
       <MauiHybridWebViewSupported Condition="'$(MauiHybridWebViewSupported)' == ''">false</MauiHybridWebViewSupported>
       <!-- FIXME: https://github.com/xamarin/xamarin-macios/issues/22065 -->
       <MobileAggressiveAttributeTrimming Condition="'$(PublishAot)' == 'true' and '$(MobileAggressiveAttributeTrimming)' == ''">false</MobileAggressiveAttributeTrimming>
+      <_EnableMauiAspire Condition="'$(_EnableMauiAspire)' == '' and '$(Configuration)' == 'Debug'">true</_EnableMauiAspire>
+      <_EnableMauiAspire Condition="'$(_EnableMauiAspire)' == ''">false</_EnableMauiAspire>
+      <_MauiAspireSetByTargets>true</_MauiAspireSetByTargets>
     </PropertyGroup>
     <ItemGroup>
       <RuntimeHostConfigurationOption Include="Microsoft.Maui.RuntimeFeature.IsIVisualAssemblyScanningEnabled"
@@ -318,6 +331,10 @@
                                       Condition="'$(EnableDiagnostics)' != ''"
                                       Value="$(EnableDiagnostics)"
                                       Trim="true" />
+      <RuntimeHostConfigurationOption Include="Microsoft.Maui.RuntimeFeature.EnableMauiAspire"
+                                      Condition="'$(_EnableMauiAspire)' != ''"
+                                      Value="$(_EnableMauiAspire)"
+                                      Trim="true" />
     </ItemGroup>
   </Target>
 </Project>

src/Core/src/Hosting/Dispatching/AppHostBuilderExtensions.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq;
 using System.Text.RegularExpressions;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
@@ -35,8 +36,34 @@ public static MauiAppBuilder ConfigureDispatching(this MauiAppBuilder builder)
 
 		public static MauiAppBuilder ConfigureEnvironmentVariables(this MauiAppBuilder builder)
 		{
+			if (!RuntimeFeature.EnableMauiAspire)
+			{
+				return builder;
+			}
+
 			IDictionary environmentVariables = Environment.GetEnvironmentVariables();
 
+#if ANDROID
+			const string androidEnvVarFilePath = "/data/local/tmp/ide-launchenv.txt";
+
+			// For Android we read the environment variables from a text file that is written to the device/emulator
+			// If the file not exists, we will use the default environment variables which is less stable
+			if (OperatingSystem.IsAndroid() && System.IO.File.Exists(androidEnvVarFilePath))
+			{
+				var envVarLines = System.IO.File.ReadAllLines(androidEnvVarFilePath);
+
+				var fileEnvironmentVariables = envVarLines
+					.Select(line => line.Split('=', 2))
+					.ToDictionary(parts => parts[0], parts => parts[1]);
+
+				// Merge file environment variables into the existing environment variables
+				foreach (var kvp in fileEnvironmentVariables)
+				{
+					environmentVariables[kvp.Key] = kvp.Value;
+				}
+			}
+#endif
+
 			string devTunnelId = environmentVariables["DEVTUNNEL_ID"]?.ToString() ?? string.Empty;
 
 			var variablesToInclude = new HashSet<string>

src/Core/src/RuntimeFeature.cs

@@ -26,6 +26,7 @@ static class RuntimeFeature
 		const bool SupportNamescopesByDefault = true;
 		const bool EnableDiagnosticsByDefault = false;
 		const bool IsMeterSupportedByDefault = true;
+		const bool EnableAspireByDefault = false;
 
 #pragma warning disable IL4000 // Return value does not match FeatureGuardAttribute 'System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute'. 
 #if NET9_0_OR_GREATER
@@ -138,6 +139,14 @@ internal set
 				AppContext.SetSwitch($"{FeatureSwitchPrefix}.{nameof(EnableMauiDiagnostics)}", value);
 			}
 		}
+
+#if NET9_0_OR_GREATER
+		[FeatureSwitchDefinition($"{FeatureSwitchPrefix}.{nameof(EnableMauiAspire)}")]
+#endif
+		public static bool EnableMauiAspire => AppContext.TryGetSwitch($"{FeatureSwitchPrefix}.{nameof(EnableMauiAspire)}", out bool isEnabled)
+				? isEnabled
+				: EnableAspireByDefault;
+
 #pragma warning restore IL4000
 	}
 }