upgrade core version to net6.0

samples/BuilderApp/BuilderApp.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net472;netcoreapp3.1;net6.0</TargetFrameworks>
+    <TargetFrameworks>net472;net6.0</TargetFrameworks>
     <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>
     <IsPackable>false</IsPackable>
   </PropertyGroup>

src/MSBuildLocator.Tests/Microsoft.Build.Locator.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net472;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net472;net6.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\MSBuildLocator\key.snk</AssemblyOriginatorKeyFile>

src/MSBuildLocator/DotNetSdkLocationHelper.cs

@@ -17,6 +17,7 @@ internal static class DotNetSdkLocationHelper
         private static readonly Regex DotNetBasePathRegex = new Regex("Base Path:(.*)$", RegexOptions.Multiline);
         private static readonly Regex VersionRegex = new Regex(@"^(\d+)\.(\d+)\.(\d+)", RegexOptions.Multiline);
         private static readonly Regex SdkRegex = new Regex(@"(\S+) \[(.*?)]$", RegexOptions.Multiline);
+        private static readonly bool IsWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
 
         public static VisualStudioInstance GetInstance(string dotNetSdkPath)
         {            
@@ -98,7 +99,13 @@ private static string FindDotnetFromEnvironmentVariable(string environmentVariab
                 string fullPathToDotnetFromRoot = Path.Combine(dotnet_root, exeName);
                 if (File.Exists(fullPathToDotnetFromRoot))
                 {
-                    return realpath(fullPathToDotnetFromRoot) ?? fullPathToDotnetFromRoot;
+                    if (!IsWindows)
+                    {
+                        fullPathToDotnetFromRoot = realpath(fullPathToDotnetFromRoot) ?? fullPathToDotnetFromRoot;
+                        return File.Exists(fullPathToDotnetFromRoot) ? Path.GetDirectoryName(fullPathToDotnetFromRoot) : null;
+                    }
+
+                    return dotnet_root;
                 }
             }
 
@@ -108,8 +115,7 @@ private static string FindDotnetFromEnvironmentVariable(string environmentVariab
         private static IEnumerable<string> GetDotNetBasePaths(string workingDirectory)
         {
             string dotnetPath = null;
-            bool isWindows = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
-            string exeName = isWindows ? "dotnet.exe" : "dotnet";
+            string exeName = IsWindows ? "dotnet.exe" : "dotnet";
 
             // First check for the DOTNET_ROOT environment variable, as it's often there as with, for example, dotnet format.
             if (IntPtr.Size == 4)
@@ -135,10 +141,15 @@ private static IEnumerable<string> GetDotNetBasePaths(string workingDirectory)
                     string filePath = Path.Combine(dir, exeName);
                     if (File.Exists(filePath))
                     {
-                        if (!isWindows)
+                        if (!IsWindows)
                         {
                             filePath = realpath(filePath) ?? filePath;
-                            if (!File.Exists(filePath))
+                            if (File.Exists(filePath))
+                            {
+                                dotnetPath = Path.GetDirectoryName(filePath);
+                                break;
+                            }
+                            else
                             {
                                 continue;
                             }

src/MSBuildLocator/Microsoft.Build.Locator.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFrameworks>net46;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net46;net6.0</TargetFrameworks>
     <DebugType>full</DebugType>
 
     <CopyLocalLockFileAssemblies>false</CopyLocalLockFileAssemblies>