[build] bootstrap a local .\bin\dotnet\ with .NET Workloads

Based on: https://github.com/jonathanpeppers/maui-workload

This adds a new `DotNet.csproj` that provisions a local .NET 6 install
into `.\bin\dotnet\`.

Next, it uses versions defined in `eng/Versions.props` as required by
.NET version bumping infrastructure (called Darc):

    <Project>
      <PropertyGroup>
        <MicrosoftNETSdkPackageVersion>6.0.100-preview.2.21155.3</MicrosoftNETSdkPackageVersion>
        <MicrosoftAndroidSdkPackageVersion>11.0.200-ci.main.148</MicrosoftAndroidSdkPackageVersion>
        <MicrosoftMacCatalystSdkPackageVersion>14.3.100-ci.main.337</MicrosoftMacCatalystSdkPackageVersion>
        <MicrosoftiOSSdkPackageVersion>14.4.100-ci.main.1192</MicrosoftiOSSdkPackageVersion>
      </PropertyGroup>
    </Project>

Next, we can use these versions to consume NuGet packages for workloads:

    <PackageDownload Include="Microsoft.NET.Workload.Android"     Version="[$(MicrosoftAndroidSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.NET.Workload.MacCatalyst" Version="[$(MicrosoftMacCatalystSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.NET.Workload.iOS"         Version="[$(MicrosoftiOSSdkPackageVersion)]" />

Then the other packs they depend on:

    <PackageDownload Include="Microsoft.Android.Ref"            Version="[$(MicrosoftAndroidSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.Android.Sdk.win-x64"    Version="[$(MicrosoftAndroidSdkPackageVersion)]" Condition="$([MSBuild]::IsOSPlatform('windows'))" />
    <PackageDownload Include="Microsoft.Android.Sdk.osx-x64"    Version="[$(MicrosoftAndroidSdkPackageVersion)]" Condition="$([MSBuild]::IsOSPlatform('osx'))" />
    <PackageDownload Include="Microsoft.Android.Sdk.BundleTool" Version="[$(MicrosoftAndroidSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.MacCatalyst.Ref"        Version="[$(MicrosoftMacCatalystSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.MacCatalyst.Sdk"        Version="[$(MicrosoftMacCatalystSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.iOS.Ref"                Version="[$(MicrosoftiOSSdkPackageVersion)]" />
    <PackageDownload Include="Microsoft.iOS.Sdk"                Version="[$(MicrosoftiOSSdkPackageVersion)]" />

After doing this, I can build .NET 6 projects with:

    > .\bin\dotnet\dotnet.exe build .\src\Controls\samples\Controls.Sample.SingleProject\Maui.Controls.Sample.SingleProject.csproj

I can even build MacCatalyst apps on Windows!

~~ Other Changes ~~

* Rework CI setup to use .\bin\dotnet\dotnet
* We don't need boots or URLs anymore
* Fixed `MSBuildTests` to use .\bin\dotnet\dotnet if found and fall
  back to the system `dotnet`

~~ TODO ~~

This obviously will change the Maui team's workflow, so:

* Need docs explaining how to do local dev, etc.

~~ What problems does this solve? ~~

* MacCatalyst builds on Windows! (offline build that checks C#)
* Building Maui always gets you the right things installed.
* Maui becoming a .NET workload will be a breeze. We can copy files
  into `.\bin\dotnet\sdk-manifests` and `.\bin\dotnet\packs`.
* We can use Darc to bump dependencies within .NET:

https://github.com/dotnet/arcade/blob/main/Documentation/Darc.md

Directory.Build.props

@@ -1,4 +1,5 @@
 <Project>
+  <Import Project="eng\Version.props" />
   <PropertyGroup>
     <_MauiBuildTasksLocation>$(_MauiBuildTasksLocation)</_MauiBuildTasksLocation>
     <_MauiBuildTasksLocation Condition="'$(_MauiBuildTasksLocation)' == ''">$(MSBuildThisFileDirectory).nuspec\</_MauiBuildTasksLocation>

Microsoft.Maui.sln

@@ -29,8 +29,9 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = ".nuspec", ".nuspec", "{7E12
 		.nuspec\Microsoft.Maui.Controls.SingleProject.targets = .nuspec\Microsoft.Maui.Controls.SingleProject.targets
 		.nuspec\Microsoft.Maui.Controls.targets = .nuspec\Microsoft.Maui.Controls.targets
 		.nuspec\Microsoft.Maui.Resizetizer.targets = .nuspec\Microsoft.Maui.Resizetizer.targets
-		.nuspec\package.ps1 = .nuspec\package.ps1
 		.nuspec\proguard.cfg = .nuspec\proguard.cfg
+		eng\package.ps1 = eng\package.ps1
+		eng\dogfood.ps1 = eng\dogfood.ps1
 	EndProjectSection
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Controls.Core", "src\Controls\src\Core\Controls.Core.csproj", "{57B8B73D-C3B5-4C42-869E-7B2F17D354AC}"

README.md

@@ -32,11 +32,31 @@ dotnet tool install Cake.Tool -g
 #### IDE
 - If you have Visual Studio 16.9 P4 installed you can open `Maui.sln` and run it from there.
 
-#### Command Line
+#### .NET 6
 
+You can run a `Cake` target to bootstrap .NET 6 in `bin\dotnet` and launch Visual Studio:
+
+```dotnetcli
+dotnet cake --target=VS-NET6
+```
+_NOTE: VS Mac is not yet supported._
+
+You can also run commands individually:
+```dotnetcli
+# Provision .NET 6 in bin\dotnet
+dotnet build src\DotNet\DotNet.csproj
+# Builds Maui MSBuild tasks & targets
+.\bin\dotnet\dotnet build Microsoft.Maui.BuildTasks-net6.sln
+# Builds the rest of Maui
+.\bin\dotnet\dotnet build Microsoft.Maui-net6.sln
+# (Windows-only) to launch Visual Studio
+.\eng\dogfood.ps1
 ```
-dotnet build src\Controls\samples\Controls.Sample.Droid\Maui.Controls.Sample.Droid-net6.csproj -t:Run
-dotnet build src\Controls\samples\Controls.Sample.iOS\Maui.Controls.Sample.iOS-net6.csproj -t:Run
+
+To build & run .NET 6 sample apps, you must continue to use `.\bin\dotnet\dotnet`:
+```dotnetcli
+.\bin\dotnet\dotnet build src\Controls\samples\Controls.Sample.Droid\Maui.Controls.Sample.Droid-net6.csproj -t:Run
+.\bin\dotnet\dotnet build src\Controls\samples\Controls.Sample.iOS\Maui.Controls.Sample.iOS-net6.csproj -t:Run
 ```
 
 ## Current News

build.cake

@@ -670,7 +670,7 @@ Task("NuGetPack")
     var settings = new DotNetCoreToolSettings
     {
         DiagnosticOutput = true,
-        ArgumentCustomization = args => args.Append($"./.nuspec/package.ps1 -configuration \"{configuration}\"")
+        ArgumentCustomization = args => args.Append($"./eng/package.ps1 -configuration \"{configuration}\"")
     };
 
    DotNetCoreTool("pwsh", settings);
@@ -886,12 +886,12 @@ Task("Android100")
 
 
 Task("VS-NET6")
-    .IsDependentOn("Clean")
     .Does(() =>
     {
-        DotNetCoreRestore("Microsoft.Maui-net6.sln");
-        DotNetCoreBuild("Microsoft.Maui-net6.sln");
-        StartVisualStudio("Microsoft.Maui-net6.sln");
+        DotNetCoreBuild("./src/DotNet/Dotnet.csproj");
+        var ext = IsRunningOnWindows() ? ".exe" : "";
+        DotNetCoreBuild("./Microsoft.Maui.BuildTasks-net6.sln", new DotNetCoreBuildSettings { ToolPath = $"./bin/dotnet/dotnet{ext}" });
+        StartVisualStudioForDotNet6();
     });
 
 Task("VS")
@@ -1206,6 +1206,22 @@ void StartVisualStudio(string sln = "./Microsoft.Maui.sln")
          StartProcess("open", new ProcessSettings{ Arguments = sln });
 }
 
+void StartVisualStudioForDotNet6(string sln = "./Microsoft.Maui-net6.sln")
+{
+    if (isCIBuild)
+        return;
+    if (!IsRunningOnWindows())
+    {
+        Information("This target is only supported on Windows.");
+        return;
+    }
+    var vsLatest = VSWhereLatest();
+    if (vsLatest == null)
+        throw new Exception("Unable to find Visual Studio!");
+    var devenv = vsLatest.CombineWithFilePath("./Common7/IDE/devenv.exe");
+    StartProcess("powershell", $"./eng/dogfood.ps1 -vs '{devenv}' -sln '{sln}'");
+}
+
 MSBuildSettings GetMSBuildSettings(PlatformTarget? platformTarget = PlatformTarget.MSIL, string buildConfiguration = null)
 {
     var buildSettings =  new MSBuildSettings {

eng/Version.props

@@ -0,0 +1,9 @@
+<Project>
+  <!--Package versions-->
+  <PropertyGroup>
+    <MicrosoftNETSdkPackageVersion>6.0.100-preview.2.21155.3</MicrosoftNETSdkPackageVersion>
+    <MicrosoftAndroidSdkPackageVersion>11.0.200-ci.main.148</MicrosoftAndroidSdkPackageVersion>
+    <MicrosoftMacCatalystSdkPackageVersion>14.3.100-ci.main.337</MicrosoftMacCatalystSdkPackageVersion>
+    <MicrosoftiOSSdkPackageVersion>14.4.100-ci.main.1192</MicrosoftiOSSdkPackageVersion>
+  </PropertyGroup>
+</Project>

eng/dogfood.ps1

@@ -0,0 +1,97 @@
+<#
+  .SYNOPSIS
+  *Windows-only* Launches Visual Studio with environment variables to use the local ./bin/dotnet/dotnet.exe.
+
+  .DESCRIPTION
+  *Windows-only* Launches Visual Studio with environment variables to use the local ./bin/dotnet/dotnet.exe.
+  Script based on:
+  https://github.com/dotnet/runtime/blob/1be117d8e7c0cd29ebc55cbcff2a7fa70604ed39/eng/build.ps1#L186-L208
+  https://github.com/dotnet/runtime/blob/1be117d8e7c0cd29ebc55cbcff2a7fa70604ed39/eng/common/tools.ps1#L109
+
+  .PARAMETER vs
+  The path to Visual Studio, defaults to:
+  "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\IDE\devenv.exe".
+
+  .PARAMETER sln
+  The path to a .sln or .project file, defaults to "Microsoft.Maui-net6.sln".
+
+  .PARAMETER modify
+  Modify the environment variables in the current session. This would
+  allow the "dotnet" command to work instead of ".\bin\dotnet\dotnet".
+  However, it would be good to do this in a new terminal session,
+  since you would have trouble running "dotnet build" if it needs to
+  provision .NET 6 and the iOS/Android workloads again.
+
+  .EXAMPLE
+  PS> .\scripts\dogfood.ps1
+
+  .EXAMPLE
+  PS> .\scripts\dogfood.ps1 -vs "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\Common7\IDE\devenv.exe"
+
+  .EXAMPLE
+  PS> .\scripts\dogfood.ps1 -sln .\path\to\MySolution.sln
+#>
+
+param(
+  [string]$vs = "${env:ProgramFiles(x86)}\Microsoft Visual Studio\2019\Enterprise\Common7\IDE\devenv.exe",
+  [string]$sln,
+  [switch]$modify
+)
+
+$dotnet=Join-Path $PSScriptRoot ../bin/dotnet/
+$dotnet=(Get-Item $dotnet).FullName
+
+if (-Not $sln) {
+    $sln=Join-Path $PSScriptRoot ../Microsoft.Maui-net6.sln
+    $sln=(Get-Item $sln).FullName
+}
+
+# Modify global.json, so the IDE can load
+$globaljson = Join-Path $PSScriptRoot ../global.json
+[xml] $xml = Get-Content (Join-Path $PSScriptRoot Version.props)
+$json = Get-Content $globaljson | ConvertFrom-Json
+$json | Add-Member sdk (New-Object -TypeName PSObject) -Force
+$json.sdk | Add-Member version $xml.Project.PropertyGroup.MicrosoftNETSdkPackageVersion -Force
+$json | ConvertTo-Json | Set-Content $globaljson
+
+# NOTE: I've not found a better way to do this
+# see: https://github.com/PowerShell/PowerShell/issues/3316
+$oldDOTNET_INSTALL_DIR=$env:DOTNET_INSTALL_DIR
+$oldDOTNET_ROOT=$env:DOTNET_ROOT
+$oldDOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR=$env:DOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR
+$oldDOTNET_MULTILEVEL_LOOKUP=$env:DOTNET_MULTILEVEL_LOOKUP
+$oldMSBuildEnableWorkloadResolver=$env:MSBuildEnableWorkloadResolver
+$oldPATH=$env:PATH
+
+try {
+    $env:DOTNET_INSTALL_DIR=$dotnet
+
+    # This tells .NET to use the bootstrapped runtime
+    $env:DOTNET_ROOT=$env:DOTNET_INSTALL_DIR
+
+    # This tells MSBuild to load the SDK from the directory of the bootstrapped SDK
+    $env:DOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR=$env:DOTNET_ROOT
+
+    # This tells .NET not to go looking for .NET in other places
+    $env:DOTNET_MULTILEVEL_LOOKUP=0
+
+    # This enables workload support inside the IDE
+    $env:MSBuildEnableWorkloadResolver=$true
+
+    # Put our local dotnet.exe on PATH first so Visual Studio knows which one to use
+    $env:PATH=($env:DOTNET_ROOT + ";" + $env:PATH)
+
+    # Launch VS
+    & "$vs" "$sln"
+} finally {
+    if (-Not $modify) {
+        $env:DOTNET_INSTALL_DIR = $oldDOTNET_INSTALL_DIR
+        $env:DOTNET_ROOT=$oldDOTNET_ROOT
+        $env:DOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR=$oldDOTNET_MSBUILD_SDK_RESOLVER_CLI_DIR
+        $env:DOTNET_MULTILEVEL_LOOKUP=$oldDOTNET_MULTILEVEL_LOOKUP
+        $env:MSBuildEnableWorkloadResolver=$oldMSBuildEnableWorkloadResolver
+        $env:PATH=$oldPATH
+    }
+}
+
+exit 0

eng/package.ps1

@@ -0,0 +1,17 @@
+param ([string] $configuration = 'Debug')
+
+$artifacts = Join-Path $PSScriptRoot ../artifacts
+
+# Bootstrap .\bin\dotnet\
+$csproj = Join-Path $PSScriptRoot ../src/DotNet/DotNet.csproj
+& dotnet build $csproj -bl:$artifacts/dotnet-$configuration.binlog
+
+$ext = if ($IsWindows) { ".exe" } else { "" }
+$dotnet = Join-Path $PSScriptRoot ../bin/dotnet/dotnet$ext
+$sln = Join-Path $PSScriptRoot ../Microsoft.Maui-net6.sln
+
+# Build with .\bin\dotnet\dotnet.exe
+& $dotnet pack $sln `
+    -c:$configuration `
+    -p:SymbolPackageFormat=snupkg `
+    -bl:$artifacts/maui-$configuration.binlog

eng/pipelines/common/build-windows.yml

@@ -16,7 +16,9 @@ steps:
       provisioning_script: $(provisionator.path)
       provisioning_extra_args: $(provisionator.extraArguments)
 
-  - template: dotnet-install.yml
+  - powershell: |
+      & dotnet build src\DotNet\DotNet.csproj -bl:${{ parameters.artifactsTargetFolder }}\$(BuildConfiguration)-dotnet.binlog
+    displayName: install .NET
 
   - powershell: |
       $(System.DefaultWorkingDirectory)/build.ps1 --target provision --TeamProject="$(System.TeamProject)"
@@ -67,7 +69,7 @@ steps:
     displayName: 'Copy Files dlls'
     inputs:
       Contents: |
-        **/bin/**/*.dll
+        src/**/bin/**/*.dll
       TargetFolder: ${{ parameters.artifactsTargetFolder }}
 
   - task: PublishBuildArtifacts@1

eng/pipelines/handlers.yml

@@ -46,7 +46,6 @@ schedules:
 
 variables:
   - template: /eng/pipelines/common/variables.yml
-  - template: /eng/pipelines/common/variables-net6.yml
   - name: LogDirectory
     value: $(Build.ArtifactStagingDirectory)/logs
   - name: provisionator.xcode
@@ -55,6 +54,8 @@ variables:
     value: '$(System.DefaultWorkingDirectory)/eng/provisioning/provisioning.csx'
   - name: provisionator.extraArguments
     value: '--v'
+  - name: DotNet.Path
+    value: $(System.DefaultWorkingDirectory)/bin/dotnet/dotnet
 
 parameters:
   - name: BuildEverything
@@ -188,27 +189,7 @@ stages:
           pool:
             name: ${{ BuildPlatform.poolName }}
             vmImage: ${{ BuildPlatform.vmImage }}
-          ${{ if eq(BuildPlatform.name, 'macos') }}:
-            variables:
-              DotNet.Root: /usr/local/share/dotnet/
-              DotNet.Tools: ~/.dotnet/tools
           steps:
-            - ${{ if eq(BuildPlatform.name, 'macos') }}:
-              - task: UseDotNet@2
-                displayName: install .NET Core 3.1
-                inputs:
-                  version: 3.1.x
-                  installationPath: $(DotNet.Root)
-            - template: common/dotnet-install.yml
-            - pwsh: |
-                dotnet tool install --global boots
-                boots ${{ BuildPlatform.bootsAndroid }}
-                boots ${{ BuildPlatform.bootsiOS }}
-                if ('${{ BuildPlatform.bootsMacCatalyst }}' -ne '') {
-                  boots ${{ BuildPlatform.bootsMacCatalyst }}
-                }
-              displayName: install .NET workloads
-              errorActionPreference: stop
             - ${{ if eq(BuildPlatform.name, 'macos') }}:
               - bash: |
                   set -x
@@ -217,7 +198,7 @@ stages:
                   /usr/libexec/PlistBuddy -c "add :AppleSdkRoot string $(dirname $(dirname $(xcode-select -p)))" ~/Library/Preferences/Xamarin/Settings.plist || true
                   cat ~/Library/Preferences/Xamarin/Settings.plist || true
                 displayName: configure vsmac xcode
-            - pwsh: ./.nuspec/package.ps1 -configuration Release
+            - pwsh: ./eng/package.ps1 -configuration Release
               displayName: pack nugets
               errorActionPreference: stop
             - task: CopyFiles@2
@@ -253,27 +234,7 @@ stages:
             pool:
               name: ${{ BuildPlatform.poolName }}
               vmImage: ${{ BuildPlatform.vmImage }}
-            ${{ if eq(BuildPlatform.name, 'macos') }}:
-              variables:
-                DotNet.Root: /usr/local/share/dotnet/
-                DotNet.Tools: ~/.dotnet/tools
             steps:
-              - ${{ if eq(BuildPlatform.name, 'macos') }}:
-                - task: UseDotNet@2
-                  displayName: install .NET Core 3.1
-                  inputs:
-                    version: 3.1.x
-                    installationPath: $(DotNet.Root)
-              - template: common/dotnet-install.yml
-              - pwsh: |
-                  dotnet tool install --global boots
-                  boots ${{ BuildPlatform.bootsAndroid }}
-                  boots ${{ BuildPlatform.bootsiOS }}
-                  if ('${{ BuildPlatform.bootsMacCatalyst }}' -ne '') {
-                    boots ${{ BuildPlatform.bootsMacCatalyst }}
-                  }
-                displayName: install .NET workloads
-                errorActionPreference: stop
               - ${{ if eq(BuildPlatform.name, 'macos') }}:
                 - bash: |
                     set -x
@@ -283,8 +244,9 @@ stages:
                     cat ~/Library/Preferences/Xamarin/Settings.plist || true
                   displayName: configure vsmac xcode
               - pwsh: |
-                  dotnet build Microsoft.Maui.BuildTasks-net6.sln -c $(BuildConfiguration) -bl:$(LogDirectory)/$(BuildConfiguration)-buildtasks.binlog
-                  dotnet build Microsoft.Maui-net6.sln -c $(BuildConfiguration) -bl:$(LogDirectory)/$(BuildConfiguration).binlog
+                  & dotnet build src\DotNet\DotNet.csproj -bl:$(LogDirectory)\$(BuildConfiguration)-dotnet.binlog
+                  & $(DotNet.Path) build Microsoft.Maui.BuildTasks-net6.sln -c $(BuildConfiguration) -bl:$(LogDirectory)/$(BuildConfiguration)-buildtasks.binlog
+                  & $(DotNet.Path) build Microsoft.Maui-net6.sln -c $(BuildConfiguration) -bl:$(LogDirectory)/$(BuildConfiguration).binlog
                 displayName: build samples
                 errorActionPreference: stop
               - task: PublishBuildArtifacts@1