setup-build: Update VS Installer (#992)

Due to a bug in the VS installer self-update process, it sometimes fails to
properly self-update, preventing the installation of the MSVC packages that we
need. In order to work around this issue, we download the newest VS installer
for the installed product and run its update process before installing the MSVC
packages.

Author: Steelskin

.github/actions/setup-build/action.yml

@@ -228,7 +228,9 @@ runs:
         $InstallerLocation = Join-Path "${env:ProgramFiles(x86)}" "Microsoft Visual Studio" "Installer"
         $VSWhere = Join-Path "${InstallerLocation}" "VSWhere.exe"
         $VSInstaller = Join-Path "${InstallerLocation}" "vs_installer.exe"
-        $InstallPath = (& "$VSWhere" -latest -products * -format json | ConvertFrom-Json).installationPath
+        $VSWhereJSON = (& "$VSWhere" -latest -products * -format json | ConvertFrom-Json)
+        $InstallPath = $VSWhereJSON.installationPath
+        $ProductID = $VSWhereJSON.productId
         $MSVCDir = Join-Path $InstallPath "VC" "Tools" "MSVC"
 
         # Compute the MSVC version package name from the MSVC version, assuming this is coming from
@@ -243,12 +245,41 @@ runs:
         $RevisionVersion = $MinorVersion - 30
         $MSVCPackageVersion = "${MajorVersion}.${MinorVersion}.${BuildVersion}.${RevisionVersion}"
 
+        # Download the latest VS Installer to update the VS Installer installation. This is needed
+        # due to a bug in the VS Installer that causes it to fail to self-update. For details, see
+        # https://developercommunity.visualstudio.com/t/Visual-Studio-Installer-randomly-fails-t/10924708
+        $VSInstallerURI = switch ($ProductID) {
+          "Microsoft.VisualStudio.Product.Community" {
+            "https://aka.ms/vs/17/release/vs_community.exe"
+          }
+          "Microsoft.VisualStudio.Product.Enterprise" {
+            "https://aka.ms/vs/17/release/vs_enterprise.exe"
+          }
+          "Microsoft.VisualStudio.Product.Professional" {
+            "https://aka.ms/vs/17/release/vs_professional.exe"
+          }
+          "Microsoft.VisualStudio.Product.BuildTools" {
+            "https://aka.ms/vs/17/release/vs_buildtools.exe"
+          }
+          default {
+            Write-Output "::error::Unsupported Visual Studio product ID: $ProductID"
+            exit 1
+          }
+        }
+        $VSProductInstaller = Join-Path "${env:TEMP}" "vs_installer.exe"
+        Invoke-WebRequest $VSInstallerURI -OutFile $VSProductInstaller -ErrorAction Stop
+
+        Write-Output "ℹ️ Updating Visual Studio Installer..."
+        $process = Start-Process "$VSProductInstaller" `
+            -PassThru `
+            -ArgumentList "--update", "--quiet", "--wait"
+        $process.WaitForExit()
+
         # Install the missing MSVC version.
         Write-Output "ℹ️ Installing MSVC packages for ${MSVCPackageVersion}..."
         $process = Start-Process "$VSInstaller" `
             -PassThru `
             -ArgumentList "modify", `
-                "--noUpdateInstaller", `
                 "--installPath", "`"$InstallPath`"", `
                 "--channelId", "https://aka.ms/vs/17/release/channel", `
                 "--quiet", "--norestart", "--nocache", `

.github/workflows/test-setup-build.yml

@@ -4,7 +4,7 @@ on:
     branches:
       - 'main'
     paths:
-      - '.github/actions/action.yml'
+      - '.github/actions/setup-build/action.yml'
       - '.github/workflows/test-setup-build.yml'
   workflow_dispatch:
     inputs: