Fix Windows Qt launcher for Visual Studio 2026

apps/arstack_studio/README.md

@@ -81,15 +81,29 @@ cmake --build build-arstack-studio --target arstack_studio --parallel
 ```
 
 On the Windows development workstation used for this phase, Qt is installed at
-`D:\Qt\6.8.3\msvc2022_64`. Build and launch with one command:
+`D:\Qt\6.8.3\msvc2022_64`. The `msvc2022_64` directory is the Qt binary-kit
+name; the launcher does **not** require the Visual Studio 2022 IDE. It discovers
+the newest installed Visual Studio x64 C++ toolchain with `vswhere`, including
+Visual Studio 2026 / MSVC v145.
+
+Build and launch with one command:
+
+```powershell
+.\apps\arstack_studio\run.cmd
+```
+
+Or call the PowerShell launcher directly:
 
 ```powershell
 .\apps\arstack_studio\run-windows.ps1
 ```
 
-Use `-NoLaunch` for a build-only verification. The launcher discovers the
-installed Visual Studio C++ toolchain with `vswhere`, reuses its bundled Ninja,
-and does not modify the user's global `PATH`.
+Use `-NoLaunch` for a build-only verification. Use `-VisualStudioRoot` only when
+you intentionally want to override automatic Visual Studio discovery. Use
+`-QtRoot` when the Qt kit is installed somewhere other than the default path.
+The launcher imports the selected Visual Studio developer environment, verifies
+`cl.exe`, and reuses Visual Studio's bundled Ninja without modifying the user's
+global `PATH`.
 
 ## P2 fast-workflow ribbon
 

apps/arstack_studio/run-windows.ps1

@@ -1,5 +1,6 @@
 param(
     [string]$QtRoot = 'D:\Qt\6.8.3\msvc2022_64',
+    [string]$VisualStudioRoot = '',
     [ValidateSet('Debug', 'Release', 'RelWithDebInfo')]
     [string]$Configuration = 'Release',
     [switch]$NoLaunch
@@ -8,15 +9,26 @@ param(
 $ErrorActionPreference = 'Stop'
 
 if (-not (Test-Path -LiteralPath (Join-Path $QtRoot 'bin\Qt6Core.dll'))) {
-    throw "Qt runtime was not found at '$QtRoot'. Install Qt 6.8.3 MSVC 2022 with Qt SerialPort first."
+    throw "Qt runtime was not found at '$QtRoot'. Install a Qt 6.x MSVC x64 kit with Qt SerialPort, or pass -QtRoot explicitly."
 }
 
 $vswhere = Join-Path ${env:ProgramFiles(x86)} 'Microsoft Visual Studio\Installer\vswhere.exe'
 if (-not (Test-Path -LiteralPath $vswhere)) {
     throw 'Visual Studio Installer (vswhere.exe) was not found.'
 }
 
-$visualStudio = & $vswhere -latest -products * -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property installationPath
+if ($VisualStudioRoot) {
+    $visualStudio = (Resolve-Path -LiteralPath $VisualStudioRoot).Path
+} else {
+    # Do not pin the launcher to a Visual Studio marketing release. vswhere
+    # selects the newest installation that actually carries the x64 C++ tools,
+    # including Visual Studio 2026 / v145 and prerelease channels.
+    $visualStudio = & $vswhere -latest -prerelease -products * `
+        -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+        -property installationPath
+    $visualStudio = $visualStudio | Select-Object -First 1
+}
+
 if (-not $visualStudio) {
     throw 'A Visual Studio installation with the C++ x64 toolchain was not found.'
 }
@@ -26,39 +38,73 @@ if (-not (Test-Path -LiteralPath $developerCommand)) {
     throw "Visual Studio developer command was not found at '$developerCommand'."
 }
 
-$environmentLines = & $env:ComSpec /s /c "`"$developerCommand`" -no_logo -arch=x64 -host_arch=x64 && set"
-$developerPath = $null
+# Import the complete Developer Command Prompt environment. Environment names
+# on Windows are case-insensitive; treating PATH and Path differently can drop
+# cl.exe from the process environment and make CMake report an unknown compiler.
+$environmentLines = & $env:ComSpec /d /s /c "call `"$developerCommand`" -no_logo -arch=x64 -host_arch=x64 >nul && set"
+if ($LASTEXITCODE -ne 0) {
+    throw "Visual Studio developer environment failed with exit code $LASTEXITCODE."
+}
+
 foreach ($line in $environmentLines) {
     $separator = $line.IndexOf('=')
     if ($separator -gt 0) {
         $name = $line.Substring(0, $separator)
         $value = $line.Substring($separator + 1)
-        if ($name -ceq 'PATH') {
-            $developerPath = $value
-        } elseif ($name -ine 'Path') {
-            [Environment]::SetEnvironmentVariable($name, $value, 'Process')
-        }
+        [Environment]::SetEnvironmentVariable($name, $value, 'Process')
     }
 }
-if ($developerPath) {
-    $env:Path = $developerPath
+
+$compiler = Get-Command cl.exe -ErrorAction SilentlyContinue
+if (-not $compiler) {
+    throw "MSVC cl.exe was not exposed by '$developerCommand'. Verify that Desktop development with C++ / MSVC x64 tools are installed in Visual Studio."
 }
 
-$ninja = Join-Path $visualStudio 'Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja\ninja.exe'
-if (-not (Test-Path -LiteralPath $ninja)) {
-    throw "The Visual Studio Ninja executable was not found at '$ninja'."
+$ninjaCandidates = @(
+    (Join-Path $visualStudio 'Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja\ninja.exe'),
+    ((Get-Command ninja.exe -ErrorAction SilentlyContinue).Source)
+) | Where-Object { $_ -and (Test-Path -LiteralPath $_) }
+$ninja = $ninjaCandidates | Select-Object -First 1
+if (-not $ninja) {
+    throw 'Ninja was not found. Install the Visual Studio CMake tools component or make ninja.exe available in PATH.'
+}
+
+$cmakeCandidates = @(
+    ((Get-Command cmake.exe -ErrorAction SilentlyContinue).Source),
+    (Join-Path $visualStudio 'Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin\cmake.exe')
+) | Where-Object { $_ -and (Test-Path -LiteralPath $_) }
+$cmake = $cmakeCandidates | Select-Object -First 1
+if (-not $cmake) {
+    throw 'CMake was not found. Install the Visual Studio CMake tools component or make cmake.exe available in PATH.'
 }
 
 $repoRoot = (Resolve-Path (Join-Path $PSScriptRoot '..\..')).Path
 $buildDirectory = Join-Path $repoRoot 'build-arstack-studio-qt'
 
-& cmake -S $PSScriptRoot -B $buildDirectory -G Ninja `
+# A failed compiler probe can leave CMAKE_CXX_COMPILER-NOTFOUND cached. Clean
+# only that broken configure state; successful incremental build caches remain.
+$cacheFile = Join-Path $buildDirectory 'CMakeCache.txt'
+if ((Test-Path -LiteralPath $cacheFile) -and
+    (Select-String -LiteralPath $cacheFile -Pattern 'CMAKE_CXX_COMPILER.*NOTFOUND' -Quiet)) {
+    Remove-Item -LiteralPath $cacheFile -Force
+    $cmakeFiles = Join-Path $buildDirectory 'CMakeFiles'
+    if (Test-Path -LiteralPath $cmakeFiles) {
+        Remove-Item -LiteralPath $cmakeFiles -Recurse -Force
+    }
+}
+
+Write-Host "Visual Studio: $visualStudio"
+Write-Host "MSVC compiler: $($compiler.Source)"
+Write-Host "Qt: $QtRoot"
+
+& $cmake -S $PSScriptRoot -B $buildDirectory -G Ninja `
     "-DCMAKE_MAKE_PROGRAM=$ninja" `
+    "-DCMAKE_CXX_COMPILER=$($compiler.Source)" `
     "-DCMAKE_PREFIX_PATH=$QtRoot" `
     "-DCMAKE_BUILD_TYPE=$Configuration"
 if ($LASTEXITCODE -ne 0) { throw "Qt configure failed with exit code $LASTEXITCODE." }
 
-& cmake --build $buildDirectory --target arstack_studio --parallel
+& $cmake --build $buildDirectory --target arstack_studio --parallel
 if ($LASTEXITCODE -ne 0) { throw "Qt build failed with exit code $LASTEXITCODE." }
 
 $executable = Join-Path $buildDirectory 'arstack_studio.exe'