v141_xp toolkit. again. and again. and...

Rethink how the Windows XP toolkit installs because the Chocolatey
installer(s) changed and broke the SIMH CI/CD build. Revert to a
previous strategy that updates the GH Windows runner image in-place with
Microsoft's vswhere and vs_installer tools.

There's some Grey Magic in how this is done, with some adapted
PowerShell code from the Chocolately PS scripts. The upshot is that
vs_installer spawns a subprocess to do the actual install, but there's
now way to get vs_installer to actually wait for that subprocess to
complete. So, the script has to look for the installer subprocesses and
poll-wait for them to finish.

.github/workflows/cmake-builds.yml

@@ -108,46 +108,103 @@ jobs:
     runs-on: windows-latest
     steps:
     - uses: actions/checkout@v3
-    ##+
+    - name: Install v141_xp (XP toolkit) and build SIMH
-    ## NOTE: This will have to change when Github updates the windows-latest
-    ## image AND when Microsoft bumps the Visual Studio year.
-    ##
-    ## Things that need updating:
-    ## - Product ID (maybe: MS seems to be very consistent with the component
-    ##   name, hasn't changed since VS 2019.)
-    ## - Channel ID
-    ##-
-    - name: Install v141_xp (XP toolkit)
       shell: pwsh
       run: |
-          $ErrorActionPreference="Stop"
+          $ErrorActionPreference = "Stop"
-          $WarningPreference="Continue"
+          $WarningPreference = "Continue"
-          $packageParams = @( "--productId", "Microsoft.VisualStudio.Product.Enterprise", 
+          $DebugPreference = "Continue"
-              "--channelId", "VisualStudio.17.Release",
-              "--add", "Microsoft.VisualStudio.Component.VC.v141.x86.x64",
-              "--add", "Microsoft.VisualStudio.Component.WinXP",
-              "--no-includeRecommended",
-              "--includeOptional",
-              "--quiet",
-              "--locale en-US" ) -join " "
-          choco install visualstudio2022-workload-nativedesktop --package-parameters $packageParams
 
-    - name: vs2022-xp build
-      shell: pwsh
-      run: |
-          $ErrorActionPreference="Stop"
-          $WarningPreference="Continue"
-          $env:ChocolateyInstall = Convert-Path "$((Get-Command choco).Path)\..\.."
-          Import-Module "$env:ChocolateyInstall\helpers\chocolateyProfile.psm1"
-          Update-SessionEnvironment
           # Fix PATH so that "C:\Strawberry" (Strawberry Perl) doesn't mess with the build
           # CMake WILL find incompatible libraries within Strawberry.
           $fixPATH = (${env:PATH}.Split(';') | `
               Where-Object { $_ -notlike "*\Strawberry\*" -and $_ -notlike "*/Strawberry/*" }) -join ';'
           $env:Path = $fixPATH
+
+          #+
+          # Update the existing Github Visual Studio installation in-place. `vswhere` may find multiple
+          # VS installations, so iterate through them all.
+          #
+          # This is Grey Magic. `vs_installer` exits almost immediately if you run it from the command
+          # line. However, `vs_installer`'s subprocesses are well known and we look for them and wait
+          # for them to terminate.
+          #
+          # GH Actions does something strange with stdout and stderr, so you won't get any
+          # indication of failure or output that shows you that something is happening.  
+          #
+          # The waiting code was adapted from the Chocolatey VS installer scripts.
+          #-
+          $vswhere = "${env:ProgramFiles} (x86)\Microsoft Visual Studio\Installer\vswhere"
+          $vsinstaller = "${env:ProgramFiles} (x86)\Microsoft Visual Studio\Installer\vs_installer.exe"
+          $vsInstallOut = "$env:TEMP\vsinstall-out.txt"
+          $vsInstallErr = "$env:TEMP\vsinstall-err.txt"
+
+          & ${vswhere} -property installationPath | `
+            Foreach-Object -process {
+              Write-Debug ("Executing: " + $vsinstaller + " " + ($Params -join " "))
+              & $vsInstaller modify --installPath "$_" --add Microsoft.VisualStudio.Component.VC.v141.x86.x64 `
+                --add Microsoft.VisualStudio.Component.WinXP --quiet `
+                2> $vsInstallErr | Write-Output
+
+              Write-Debug ('Looking for running VS installer processes')
+              $vsinstallerProcesses = @('vs_installershell', 'vs_installerservice')
+              do
+              {
+                  $vsInstallerRemaining = Get-Process -Name $vsinstallerProcesses -ErrorAction SilentlyContinue | Where-Object { $null -ne $_ -and -not $_.HasExited }
+                  $vsInstallerProcessCount = ($vsInstallerRemaining | Measure-Object).Count
+                  if ($vsInstallerProcessCount -gt 0)
+                  {
+                      try
+                      {
+                          Write-Debug "Found $vsInstallerProcessCount still running Visual Studio installer processes which are known to exit asynchronously:"
+                          $vsInstallerRemaining | Sort-Object -Property Name, Id | ForEach-Object { '[{0}] {1}' -f $_.Id, $_.Name } | Write-Debug
+                          Write-Debug ('Giving the processes some time to exit')
+                          $vsInstallerRemaining | Wait-Process -Timeout 1 -ErrorAction SilentlyContinue
+                          Write-Debug ('Looking for running VS installer processes')
+                      }
+                      finally
+                      {
+                          $vsInstallerRemaining | ForEach-Object { $_.Dispose() }
+                          $vsInstallerRemaining = $null
+                      }
+                  }
+              }
+              while ($vsInstallerProcessCount -gt 0)
+            }
+
+          if ((Test-Path $vsInstallOut -PathType Leaf) -and (Get-Item $vsInstallOut).length -gt 0kb)
+          {
+            Write-Output "-- vsinstaller output:"
+            Get-Content $vsInstallOut
+          }
+          else
+          {
+            Write-Debug "-- No vsinstaller output."
+          }
+
+          if ((Test-Path $vsInstallErr -PathType Leaf) -and (Get-Item $vsInstallErr).length -gt 0kb)
+          {
+            Write-Output "-- vsinstaller error output:"
+            Get-Content $vsInstallErr
+          }
+          else
+          {
+            Write-Debug "-- No vsinstaller error/diag output."
+          }
+
+          #+
+          # The GH Windows runner image documentation says that the VSSetup module is installed, from
+          # whence Get-VSSetupInstance and Select-VSSetupInstance are imported. This step is pure
+          # paranoia, ensuring that we really, truly and honestly have WinXP support.
+          #-
+          Write-Debug "Get-VSSetupInstance/Select-VSSetupInstance"
+          Get-VSSetupInstance -All | Select-VSSetupInstance -Require 'Microsoft.VisualStudio.Component.WinXP' -Latest
+
           ## Don't use LTO for XP. XP compatibility comes from VS2017 -- MS is
           ## at VS2022. There are likely legacy bugs that have been fixed.
           ./cmake/cmake-builder.ps1 -flavor vs2022-xp -config Release -clean -verbose -notest -cpack_suffix win32-xp
+
+
     - name: SIMH simulator suite test
       shell: pwsh
       run: |