Use MuxerPath to determine location to dotnet.exe

Fixes $50

RazorViewCompilation.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26516.2
+VisualStudioVersion = 15.0.26430.6
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Mvc.Razor.ViewCompilation", "src\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.csproj", "{4339FC9B-AEC6-442A-B413-A41555ED76C7}"
 EndProject
@@ -58,6 +58,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tools", "tools", "{75244EBD
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Mvc.Razor.ViewCompilation-x86", "tools\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation-x86\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation-x86.csproj", "{DFB86DBD-17DA-4A97-A4FD-00D6E5160B3D}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks", "src\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks.csproj", "{996D4DEB-1701-435E-8048-1E65790C2050}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -284,6 +286,18 @@ Global
 		{DFB86DBD-17DA-4A97-A4FD-00D6E5160B3D}.Release|x64.Build.0 = Release|Any CPU
 		{DFB86DBD-17DA-4A97-A4FD-00D6E5160B3D}.Release|x86.ActiveCfg = Release|Any CPU
 		{DFB86DBD-17DA-4A97-A4FD-00D6E5160B3D}.Release|x86.Build.0 = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|x64.Build.0 = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Debug|x86.Build.0 = Debug|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|Any CPU.Build.0 = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|x64.ActiveCfg = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|x64.Build.0 = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|x86.ActiveCfg = Release|Any CPU
+		{996D4DEB-1701-435E-8048-1E65790C2050}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -307,5 +321,6 @@ Global
 		{779BACC4-B20E-4F73-A9C7-350443CF1941} = {0DC7C88C-E3DB-46DF-B47E-AC5ECB2A16B7}
 		{D838D8E1-997A-4053-BB2A-2CBDE9F09A0B} = {0DC7C88C-E3DB-46DF-B47E-AC5ECB2A16B7}
 		{DFB86DBD-17DA-4A97-A4FD-00D6E5160B3D} = {75244EBD-DFBD-4C4B-9543-C135AC142C7F}
+		{996D4DEB-1701-435E-8048-1E65790C2050} = {02F7AA35-91AF-491E-9F0E-03CFAF86C720}
 	EndGlobalSection
 EndGlobal

build/common-testapps.props

@@ -2,6 +2,7 @@
   <Import Project="dependencies.props" />
   <PropertyGroup>
     <TestIncludeViewCompilationTargets Condition="'$(TestIncludeViewCompilationTargets)'==''">$(MvcRazorCompileOnPublish)</TestIncludeViewCompilationTargets>
+    <_MvcViewCompilationTasksPath>$(MSBuildThisFileDirectory)..\src\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks\bin\$(Configuration)\netstandard2.0\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks.dll</_MvcViewCompilationTasksPath>
   </PropertyGroup>
 
   <Import Project="..\src\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation\build\netstandard2.0\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.targets"

build/dependencies.props

@@ -3,6 +3,7 @@
     <AspNetCoreVersion>2.0.0-*</AspNetCoreVersion>
     <AspNetCoreIntegrationTestingVersion>0.4.0-*</AspNetCoreIntegrationTestingVersion>
     <InternalAspNetCoreSdkVersion>2.1.0-*</InternalAspNetCoreSdkVersion>
+    <MsBuildPackageVersions>15.1.1012</MsBuildPackageVersions>
     <NETStandardImplicitPackageVersion>2.0.0-*</NETStandardImplicitPackageVersion>
     <NETStandardLibraryNETFrameworkVersion>2.0.0-*</NETStandardLibraryNETFrameworkVersion>
     <RuntimeFrameworkVersion Condition="'$(TargetFramework)'=='netcoreapp2.0'">2.0.0-*</RuntimeFrameworkVersion>

build/repo.props

@@ -0,0 +1,5 @@
+<Project>
+  <ItemGroup>
+    <ExcludeFromPack Include="$(RepositoryRoot)src\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks.csproj" />
+  </ItemGroup>
+</Project>

src/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks/GetDotNetHost.cs

@@ -0,0 +1,21 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+using Microsoft.Extensions.CommandLineUtils;
+
+namespace Microsoft.AspNetCore.BuildTools
+{
+    public class GetDotNetHost : Task
+    {
+        [Output]
+        public string MuxerPath { get; set; }
+
+        public override bool Execute()
+        {
+            MuxerPath = DotNetMuxer.MuxerPathOrDefault();
+            return true;
+        }
+    }
+}

src/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <Import Project="..\..\build\common.props" />
+
+  <PropertyGroup>
+    <Description>Microsoft Build Tasks supporting  Razor view compilation.</Description>
+    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Build.Tasks.Core" Version="$(MsBuildPackageVersions)" />
+    <PackageReference Include="Microsoft.Extensions.CommandLineUtils.Sources" Version="$(AspNetCoreVersion)" PrivateAssets="All" />
+  </ItemGroup>
+
+</Project>

src/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.csproj

@@ -11,11 +11,13 @@
     <PreserveCompilationContext>true</PreserveCompilationContext>
     <OutputType>exe</OutputType>
     <X86ProjectDirectory>..\..\tools\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation-x86\</X86ProjectDirectory>
+    <TasksProjectDirectory>..\Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks\</TasksProjectDirectory>
     <IncludeBuildOutput>false</IncludeBuildOutput>
   </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="$(X86ProjectDirectory)$(MSBuildThisFileName)-x86.csproj" PrivateAssets="true" ReferenceOutputAssembly="false" Condition="'$(TargetFramework)'=='net461'" />
+    <ProjectReference Include="$(TasksProjectDirectory)Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.Tasks.csproj"  PrivateAssets="true" ReferenceOutputAssembly="false" />
 
     <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.RazorPages" Version="$(AspNetCoreVersion)" />
@@ -25,6 +27,7 @@
   <ItemGroup>
     <None Include="build\**\*.*" Pack="true" PackagePath="%(Identity)" />
     <None Include="$(OutputPath)netcoreapp2.0\$(AssemblyName).dll" Pack="true" PackagePath="build\netstandard2.0\$(AssemblyName).dll" />
+    <None Include="$(TasksProjectDirectory)bin\$(Configuration)\netstandard2.0\$(AssemblyName).Tasks.dll" Pack="true" PackagePath="build\netstandard2.0\$(AssemblyName).Tasks.dll" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(OS)'=='Windows_NT'">

src/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation/build/netstandard2.0/Microsoft.AspNetCore.Mvc.Razor.ViewCompilation.targets

@@ -25,21 +25,28 @@
     <CallTarget Targets="_MvcRazorPrecompile" />
   </Target>
 
-  <Target
+  <Target Name="_MvcRazorPrecompile" DependsOnTargets="_RunForCore;_RunForDesktop" />
-    Name="_MvcRazorPrecompile"
-    DependsOnTargets="_RunForCore;_RunForDesktop">
 
-  </Target>
+  <PropertyGroup>
+    <_MvcViewCompilationTasksPath Condition="'$(_MvcViewCompilationTasksPath)'==''">$(MSBuildThisFileDirectory)$(MSBuildThisFileName).Tasks.dll</_MvcViewCompilationTasksPath>
+  </PropertyGroup>
+
+  <UsingTask TaskName="GetDotNetHost" AssemblyFile="$(_MvcViewCompilationTasksPath)" />
 
   <Target
     Name="_RunForCore"
     DependsOnTargets="_CreateResponseFileForMvcRazorPrecompile"
     Condition="'$(TargetFrameworkIdentifier)'=='.NETCoreApp'">
 
+    <GetDotNetHost Condition="'$(MvcRazorRunCommand)'==''">
+      <Output TaskParameter="MuxerPath" PropertyName="MvcRazorRunCommand" />
+    </GetDotNetHost>
+
     <PropertyGroup>
       <_MvcViewCompilationBinaryPath Condition="'$(_MvcViewCompilationBinaryPath)'==''">$(MSBuildThisFileDirectory)$(MSBuildThisFileName).dll</_MvcViewCompilationBinaryPath>
 
-      <ExecArgs>dotnet exec --runtimeconfig &quot;$(ProjectRuntimeConfigFilePath)&quot;</ExecArgs>
+      <ExecArgs>&quot;$(MvcRazorRunCommand)&quot; exec</ExecArgs>
+      <ExecArgs>$(ExecArgs) --runtimeconfig &quot;$(ProjectRuntimeConfigFilePath)&quot;</ExecArgs>
       <ExecArgs>$(ExecArgs) --depsfile &quot;$(ProjectDepsFilePath)&quot;</ExecArgs>
       <ExecArgs>$(ExecArgs) &quot;$(_MvcViewCompilationBinaryPath)&quot;</ExecArgs>
       <ExecArgs>$(ExecArgs) @&quot;$(_MvcRazorResponseFilePath)&quot;</ExecArgs>