try to use invoking .net runtime instead of looking it up from path

src/Runner.Client/Program.cs

@@ -264,7 +264,7 @@ private static async Task<int> CreateRunner(string binpath, Parameters parameter
                 Console.WriteLine(e.Data);
             };
 #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
-            var dotnet = WhichUtil.Which("dotnet", true);
+            var dotnet = Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
             string ext = ".dll";
 #else
             string ext = IOUtil.ExeExtension;
@@ -497,7 +497,7 @@ private static async Task<int> CreateExternalRunner(string binpath, Parameters p
                             // Use embedded runner to configure external github agent, otherwise only port 80 or 443 are possible to use for configuration
                         #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
                             arguments = $"\"{Path.Join(binpath, "Runner.Listener.dll")}\" {arguments}";
-                            file = WhichUtil.Which("dotnet", true);
+                            file = Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
                         #else
                             file = Path.Join(binpath, $"Runner.Listener{ext}");
                         #endif
@@ -535,7 +535,7 @@ private static async Task<int> CreateExternalRunner(string binpath, Parameters p
                                     if(!System.Runtime.InteropServices.RuntimeInformation.IsOSPlatform(System.Runtime.InteropServices.OSPlatform.Windows)) {
                                         #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
                                             arguments = $"\"{Path.Join(binpath, "Runner.Client.dll")}\" spawn \"{file}\" {arguments}";
-                                            file = WhichUtil.Which("dotnet", true);
+                                            file = Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
                                         #else
                                             arguments = $"spawn \"{file}\" {arguments}";
                                             file = Path.Join(binpath, $"Runner.Client{ext}");
@@ -1293,7 +1293,7 @@ static int Main(string[] args)
                                 invoker.ErrorDataReceived += _out;
                             }
 #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
-                            var dotnet = WhichUtil.Which("dotnet", true);
+                            var dotnet = Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
                             string ext = ".dll";
 #else
                             string ext = IOUtil.ExeExtension;

src/Runner.Language.Server/Runner.Language.Server.csproj

@@ -17,6 +17,8 @@
   </PropertyGroup>
   <PropertyGroup Condition="'$(WASM)' != '1'">
     <OutputType>Exe</OutputType>
+      <!-- See https://github.com/dotnet/sdk/issues/18116#issuecomment-855266314 -->
+    <ValidateExecutableReferencesMatchSelfContained>false</ValidateExecutableReferencesMatchSelfContained>
   </PropertyGroup>
 
   <ItemGroup>

src/Runner.Listener/JobDispatcher.cs

@@ -473,7 +473,7 @@ private async Task RunAsync(Pipelines.AgentJobRequestMessage message, string orc
                                 string workerFileName = Path.Combine(assemblyDirectory, $"{_workerProcessName}{ext}");
                                 string arguments = "spawnclient " + pipeHandleOut + " " + pipeHandleIn;
 #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
-                                var dotnet = WhichUtil.Which("dotnet", true);
+                                var dotnet = global::Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
                                 arguments = $"\"{workerFileName}\" {arguments}";
                                 workerFileName = dotnet;
 #endif

src/Runner.Sdk/Util/IOUtil.cs

@@ -558,5 +558,13 @@ private static void RemoveReadOnly(FileSystemInfo item)
                 item.Attributes = item.Attributes & ~FileAttributes.ReadOnly;
             }
         }
+
+        public static string GetDotnet() {
+            var procPath = Environment.ProcessPath;
+            if(Path.GetFileNameWithoutExtension(procPath) == "dotnet" && Path.GetExtension(procPath) == ExeExtension) {
+                return procPath;
+            }
+            return WhichUtil.Which("dotnet", true);
+        }
     }
 }

src/Runner.Worker/RunnerPluginManager.cs

@@ -102,7 +102,7 @@ public async Task RunPluginActionAsync(IExecutionContext context, string plugin,
             string arguments = $"action \"{plugin}\"";
 
 #if !OS_LINUX && !OS_WINDOWS && !OS_OSX && !X64 && !X86 && !ARM && !ARM64
-            var dotnet = WhichUtil.Which("dotnet", true);
+            var dotnet = global::Sdk.Utils.DotNetMuxer.MuxerPath ?? WhichUtil.Which("dotnet", true);
             arguments = $"\"{file}\" {arguments}";
             file = dotnet;
 #endif

src/Sdk/Utils/DotNetMuxer.cs

@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+// System.AppContext.GetData is not available in these frameworks
+
+/// https://github.com/dotnet/aspnetcore/blob/main/src/Shared/CommandLineUtils/Utilities/DotNetMuxer.cs
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+namespace Sdk.Utils
+{
+/// <summary>
+/// Utilities for finding the "dotnet.exe" file from the currently running .NET Core application
+/// </summary>
+public static class DotNetMuxer
+{
+    private const string MuxerName = "dotnet";
+
+    static DotNetMuxer()
+    {
+        MuxerPath = TryFindMuxerPath();
+    }
+
+    /// <summary>
+    /// The full filepath to the .NET Core muxer.
+    /// </summary>
+    public static string? MuxerPath { get; }
+
+    /// <summary>
+    /// Finds the full filepath to the .NET Core muxer,
+    /// or returns a string containing the default name of the .NET Core muxer ('dotnet').
+    /// </summary>
+    /// <returns>The path or a string named 'dotnet'.</returns>
+    public static string MuxerPathOrDefault()
+        => MuxerPath ?? MuxerName;
+
+    private static string? TryFindMuxerPath()
+    {
+        var expectedFileName = MuxerName;
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            expectedFileName += ".exe";
+        }
+
+        // If the currently running process is dotnet(.exe), return that path
+        var mainModuleFullPath = Process.GetCurrentProcess().MainModule?.FileName;
+        var mainModuleFileName = Path.GetFileName(mainModuleFullPath);
+        if (string.Equals(expectedFileName, mainModuleFileName, StringComparison.OrdinalIgnoreCase))
+        {
+            return mainModuleFullPath;
+        }
+
+        // The currently running process may not be dotnet(.exe). For example,
+        // it might be "testhost(.exe)" when running tests.
+        // In this case, we can get the location where the CLR is installed,
+        // and find dotnet(.exe) relative to that path.
+        var runtimeDirectory = RuntimeEnvironment.GetRuntimeDirectory();
+        var candidateDotNetExePath = Path.Combine(runtimeDirectory, "..", "..", "..", expectedFileName);
+        if (File.Exists(candidateDotNetExePath))
+        {
+            var normalizedPath = Path.GetFullPath(candidateDotNetExePath);
+            return normalizedPath;
+        }
+
+        return null;
+    }
+}
+}

src/runner-server-vscode/package.json

@@ -43,7 +43,7 @@
 		]
 	},
 	"scripts": {
-		"build": "dotnet publish ../Runner.Language.Server --no-self-contained -p:BUILD_OS=Any -p:RuntimeFrameworkVersion=6.0.0 --output native"
+		"build": "dotnet publish ../Runner.Language.Server --no-self-contained -p:UseAppHost=false -p:BUILD_OS=Any -p:RuntimeFrameworkVersion=6.0.0 --output native"
 	},
 	"devDependencies": {
 		"@types/vscode": "^1.73.0",

src/runner-server-web-vscode/package.json

@@ -17,6 +17,17 @@
 	"activationEvents": [
 		"onLanguage:yaml"
 	],
+	"contributes": {
+		"semanticTokenScopes": [
+			{
+				"scopes": {
+					"constant.defaultLibrary": ["constant.language"],
+					"constant.numeric": ["constant.numeric"],
+					"punctuation": ["meta.embedded"]
+				}
+			}
+		]
+	},
 	"browser": "./client/dist/browserClientMain",
 	"scripts": {
 		"vscode:prepublish": "npm run build",