Stop repeated installer toolchain startup failures

.github/CI.md

@@ -10,6 +10,12 @@ dependency/license audit, secret scan, Windows installer build, workflow syntax
 check, or installer release automation test fails or is skipped.
 The job summary links to the run; failed step logs contain diagnostic details.
 The fresh Windows installer is saved as a workflow artifact for seven days.
+The installer job also runs Windows PowerShell 5.1 toolchain-manager regression tests
+and silent packaged Setup tests. A local mock WinGet covers installed and missing
+tools, ordinary package failures, and initialization errors `142`/`0xc0000142` without
+downloading toolchains. Packaged tests verify a single PowerShell transcript for all
+selected languages, that a failing WinGet is not retried for later languages, and
+that bundled-only Setup does not start the toolchain manager.
 
 ## Installer releases
 

.github/workflows/quality.yml

@@ -181,6 +181,11 @@ jobs:
           if (-not (Get-ChildItem 'dist/RusticGameEngine-Setup-*.exe' -ErrorAction SilentlyContinue)) {
             throw 'No fresh Windows installer was produced.'
           }
+      - name: Test toolchain failures and packaged Setup
+        run: |
+          $installer = Get-ChildItem 'dist/RusticGameEngine-Setup-*.exe' | Sort-Object LastWriteTime -Descending | Select-Object -First 1
+          powershell -NoProfile -ExecutionPolicy Bypass -File ./tools/test-language-toolchains.ps1 -InstallerPath $installer.FullName
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
       - uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
         with:
           name: windows-installer

.github/workflows/windows-installer.yml

@@ -32,6 +32,11 @@ jobs:
             !/Engine/dist/
       - name: Build Windows installer
         run: ./tools/build-windows-installer.ps1
+      - name: Test toolchain failures and packaged Setup
+        run: |
+          $installer = Get-ChildItem 'dist/RusticGameEngine-Setup-*.exe' | Sort-Object LastWriteTime -Descending | Select-Object -First 1
+          powershell -NoProfile -ExecutionPolicy Bypass -File ./tools/test-language-toolchains.ps1 -InstallerPath $installer.FullName
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
       - name: Upload installer
         uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
         with:

Engine/README.md

@@ -70,6 +70,30 @@ removed through Windows Installed Apps. Because it is a desktop application, its
 folder is not added to `PATH` by default; pass `-InstallDirectoryOnPath` to select that
 installer option by default.
 
+The builder validates the installer script with Inno Setup before compiling the
+engine. This preflight omits the unbuilt binaries and disables output; it cannot
+produce a distributable installer.
+
+Setup checks and installs all selected optional toolchains in one hidden,
+noninteractive PowerShell process as the original user. Already-installed toolchains
+are skipped. If PowerShell cannot start, or WinGet returns an initialization failure
+(`142` or `0xc0000142`), Setup reports the optional-toolchain failure once and leaves
+the installed engine usable with its bundled languages. Setup always saves a log in
+`%TEMP%` named `Setup Log ...txt`; the failure dialog gives its exact path. To choose
+a persistent location, run `RusticGameEngine-Setup-<version>.exe /LOG="C:\path\setup.log"`.
+If PowerShell started, its transcript is in the original user's
+`%LOCALAPPDATA%\Rustic Game Engine\logs\toolchain-install.log`. Repair the failing
+PowerShell or Microsoft App Installer installation before retrying **Language
+Toolchain Manager**. The Setup log records launch errors and exit codes even when
+the transcript could not be created.
+
+On Windows, run the toolchain regression tests with
+`powershell -NoProfile -ExecutionPolicy Bypass -File .\tools\test-language-toolchains.ps1`.
+Pass `-InstallerPath .\dist\RusticGameEngine-Setup-<version>.exe` to also test silent
+packaged Setup with all optional languages, simulated WinGet initialization failures,
+and bundled languages only. The tests use a local mock WinGet executable and never
+download or install external toolchains.
+
 See [`CONTRIBUTING.md`](CONTRIBUTING.md) for the decision-record and project-file safety
 conventions.
 

Engine/docs/GAMEPLAY_PROGRAMMING.md

@@ -236,6 +236,18 @@ installs every selected item through Windows Package Manager. Lua, JavaScript, a
 HTML/CSS are bundled. Additional toolchains can be installed later using **Rustic Game
 Engine > Language Toolchain Manager** in the Start menu or by rerunning Setup.
 
+Setup checks all selected toolchains in one hidden PowerShell process, skipping
+already-installed tools. If PowerShell cannot start or WinGet reports initialization
+error `142` or `0xc0000142`, it stops the batch and reports the optional-toolchain
+failure once. Rustic remains installed with its bundled languages. These are distinct
+error codes; retain the full message and the failing executable when diagnosing them.
+The failure dialog shows the Setup log path (`Setup Log ...txt` in `%TEMP%` by default).
+Use `/LOG="C:\path\setup.log"` to choose a persistent log location. If PowerShell started,
+check the original user's `%LOCALAPPDATA%\Rustic Game Engine\logs\toolchain-install.log`
+for package details and WinGet output. Otherwise, the Setup log records the PowerShell
+startup failure. Repair the failing PowerShell or Microsoft App Installer installation
+before retrying **Language Toolchain Manager**. Setup does not require Windows Terminal.
+
 ## HTML/CSS content
 
 HTML/CSS/PHP UI content is confined to the project's `ui/` directory. `.html` and

Engine/installer/RusticGameEngine.iss

@@ -35,6 +35,7 @@ WizardStyle=modern
 MinVersion=10.0
 CloseApplications=yes
 RestartApplications=no
+SetupLogging=yes
 
 [Languages]
 Name: "english"; MessagesFile: "compiler:Default.isl"
@@ -71,12 +72,14 @@ Source: "..\licenses\ogg-BSD-3-Clause.txt"; DestDir: "{app}\licenses"; Flags: ig
 Source: "..\licenses\opus-pure-BSD-3-Clause.txt"; DestDir: "{app}\licenses"; Flags: ignoreversion
 Source: "..\licenses\opus-pure-ATTRIBUTION.md"; DestDir: "{app}\licenses"; Flags: ignoreversion
 Source: "..\licenses\Audio-Decoders-NOTICE.md"; DestDir: "{app}\licenses"; Flags: ignoreversion
+#ifndef InstallerPreflight
 Source: "..\target\distribution\rustic-luau-host.exe"; DestDir: "{app}"; Flags: ignoreversion
 Source: "..\target\distribution\rustic-agent-backend.exe"; DestDir: "{app}"; Flags: ignoreversion
 Source: "..\target\distribution\rustic-project-manager.exe"; DestDir: "{app}"; Flags: ignoreversion
 Source: "..\target\distribution\rustic-editor.exe"; DestDir: "{app}"; Flags: ignoreversion
 Source: "..\target\distribution\rustic-runtime.exe"; DestDir: "{app}"; Flags: ignoreversion
 Source: "..\target\distribution\rustic-asset-worker.exe"; DestDir: "{app}"; Flags: ignoreversion
+#endif
 Source: "..\tools\manage-language-toolchains.ps1"; DestDir: "{app}\tools"; Flags: ignoreversion
 
 [Icons]
@@ -93,111 +96,76 @@ Filename: "{app}\rustic-agent-backend.exe"; Parameters: "--install-user-integrat
 Filename: "{app}\{#AppExeName}"; Description: "Launch {#AppName}"; Flags: nowait postinstall skipifsilent
 
 [Code]
-function IsLanguageToolchainInstalled(Language: String): Boolean;
-var
-  ResultCode: Integer;
-begin
-  Result := ExecAsOriginalUser(
-    ExpandConstant('{sys}\WindowsPowerShell\v1.0\powershell.exe'),
-    '-NoProfile -ExecutionPolicy Bypass -File "' +
-      ExpandConstant('{app}\tools\manage-language-toolchains.ps1') +
-      '" -Languages "' + Language + '" -CheckOnly',
-    ExpandConstant('{app}'), SW_HIDE, ewWaitUntilTerminated, ResultCode
-  ) and (ResultCode = 0);
-end;
-
-function SelectedLanguageCount(): Integer;
-begin
-  Result := 0;
-  if WizardIsComponentSelected('languages\python') and not IsLanguageToolchainInstalled('Python') then Result := Result + 1;
-  if WizardIsComponentSelected('languages\csharp') and not IsLanguageToolchainInstalled('CSharp') then Result := Result + 1;
-  if WizardIsComponentSelected('languages\ccpp') and not IsLanguageToolchainInstalled('CCpp') then Result := Result + 1;
-  if WizardIsComponentSelected('languages\java') and not IsLanguageToolchainInstalled('Java') then Result := Result + 1;
-  if WizardIsComponentSelected('languages\php') and not IsLanguageToolchainInstalled('Php') then Result := Result + 1;
-end;
-
-function AnyOptionalLanguageSelected(): Boolean;
+procedure AddSelectedLanguage(Component, Language: String; var Languages: String);
 begin
-  Result :=
-    WizardIsComponentSelected('languages\python') or
-    WizardIsComponentSelected('languages\csharp') or
-    WizardIsComponentSelected('languages\ccpp') or
-    WizardIsComponentSelected('languages\java') or
-    WizardIsComponentSelected('languages\php');
+  if WizardIsComponentSelected(Component) then
+  begin
+    if Languages <> '' then Languages := Languages + ',';
+    Languages := Languages + Language;
+  end;
 end;
 
-procedure InstallLanguageToolchain(Language, DisplayName: String;
-  var CompletedCount: Integer; TotalCount: Integer; var Failures: String);
+procedure InstallSelectedLanguageToolchains();
 var
+  Languages: String;
+  Failure: String;
+  Started: Boolean;
   ResultCode: Integer;
 begin
-  WizardForm.StatusLabel.Caption := Format(
-    'Installing %s (%d of %d)...', [DisplayName, CompletedCount + 1, TotalCount]);
-  WizardForm.ProgressGauge.Position := CompletedCount;
+  Languages := '';
+  AddSelectedLanguage('languages\python', 'Python', Languages);
+  AddSelectedLanguage('languages\csharp', 'CSharp', Languages);
+  AddSelectedLanguage('languages\ccpp', 'CCpp', Languages);
+  AddSelectedLanguage('languages\java', 'Java', Languages);
+  AddSelectedLanguage('languages\php', 'Php', Languages);
+  if Languages = '' then Exit;
+
+  WizardForm.StatusLabel.Caption := 'Checking and installing selected gameplay language toolchains...';
   WizardForm.Refresh;
 
-  if not ExecAsOriginalUser(
-    ExpandConstant('{sys}\WindowsPowerShell\v1.0\powershell.exe'),
-    '-NoProfile -ExecutionPolicy Bypass -File "' +
-      ExpandConstant('{app}\tools\manage-language-toolchains.ps1') +
-      '" -Languages "' + Language + '" -LogPath "' +
-      ExpandConstant('{localappdata}\Rustic Game Engine\logs\toolchain-install.log') + '"',
-    ExpandConstant('{app}'), SW_HIDE, ewWaitUntilTerminated, ResultCode
-  ) or (ResultCode <> 0) then
-  begin
-    if Failures <> '' then Failures := Failures + ', ';
-    Failures := Failures + DisplayName;
+  // The manager checks installed packages itself. Launch it once, rather than
+  // starting a new PowerShell host for each check and each installation.
+  Log('Selected optional language toolchains: ' + Languages);
+  Failure := '';
+  ResultCode := -1;
+  try
+    Started := ExecAsOriginalUser(
+      ExpandConstant('{sys}\WindowsPowerShell\v1.0\powershell.exe'),
+      '-NoProfile -NonInteractive -ExecutionPolicy Bypass -File "' +
+        ExpandConstant('{app}\tools\manage-language-toolchains.ps1') +
+        '" -Languages "' + Languages + '" -Setup',
+      ExpandConstant('{app}'), SW_HIDE, ewWaitUntilTerminated, ResultCode
+    );
+    if not Started then
+      Failure := Format('Could not start PowerShell: Windows error %d (%s).', [ResultCode, SysErrorMessage(ResultCode)])
+    else if ResultCode <> 0 then
+      Failure := Format('Language Toolchain Manager exited with code %d (0x%.8x).', [ResultCode, ResultCode]);
+  except
+    Failure := 'Could not start Language Toolchain Manager: ' + GetExceptionMessage;
   end;
 
-  CompletedCount := CompletedCount + 1;
-  WizardForm.ProgressGauge.Position := CompletedCount;
+  if Failure <> '' then
+  begin
+    Log(Failure);
+    WizardForm.StatusLabel.Caption := 'Rustic is installed; optional toolchain installation needs attention.';
+    // Keep the engine usable and report one failure, including host failures
+    // that occur before PowerShell can create its own transcript.
+    SuppressibleMsgBox(
+      'Rustic Game Engine was installed, but optional language toolchain installation did not finish.' + #13#10 + #13#10 +
+      Failure + #13#10 + #13#10 +
+      'You can retry from Language Toolchain Manager in the Start menu.' + #13#10 +
+      'Setup log: ' + ExpandConstant('{log}') + #13#10 +
+      'Toolchain log (if PowerShell started): %LOCALAPPDATA%\Rustic Game Engine\logs\toolchain-install.log',
+      mbError, MB_OK, IDOK);
+  end;
+  if Failure = '' then
+    WizardForm.StatusLabel.Caption := 'Selected gameplay language toolchains are installed.';
   WizardForm.Refresh;
 end;
 
 procedure CurStepChanged(CurStep: TSetupStep);
-var
-  CompletedCount: Integer;
-  TotalCount: Integer;
-  Failures: String;
 begin
-  if CurStep = ssPostInstall then
-  begin
-    TotalCount := SelectedLanguageCount();
-    if TotalCount > 0 then
-    begin
-      CompletedCount := 0;
-      Failures := '';
-      WizardForm.ProgressGauge.Min := 0;
-      WizardForm.ProgressGauge.Max := TotalCount;
-      WizardForm.ProgressGauge.Position := 0;
-
-      if WizardIsComponentSelected('languages\python') and not IsLanguageToolchainInstalled('Python') then
-        InstallLanguageToolchain('Python', 'Python 3.14', CompletedCount, TotalCount, Failures);
-      if WizardIsComponentSelected('languages\csharp') and not IsLanguageToolchainInstalled('CSharp') then
-        InstallLanguageToolchain('CSharp', '.NET SDK 10 for C#', CompletedCount, TotalCount, Failures);
-      if WizardIsComponentSelected('languages\ccpp') and not IsLanguageToolchainInstalled('CCpp') then
-        InstallLanguageToolchain('CCpp', 'LLVM for C and C++', CompletedCount, TotalCount, Failures);
-      if WizardIsComponentSelected('languages\java') and not IsLanguageToolchainInstalled('Java') then
-        InstallLanguageToolchain('Java', 'Microsoft OpenJDK 21', CompletedCount, TotalCount, Failures);
-      if WizardIsComponentSelected('languages\php') and not IsLanguageToolchainInstalled('Php') then
-        InstallLanguageToolchain('Php', 'PHP 8.4 CLI', CompletedCount, TotalCount, Failures);
-
-      WizardForm.StatusLabel.Caption := 'Finished installing gameplay language toolchains.';
-      WizardForm.Refresh;
-
-      if Failures <> '' then
-        MsgBox(Format(
-          'Rustic Game Engine was installed, but these optional language toolchains could not be installed: %s.' + #13#10 + #13#10 +
-          'You can retry from Language Toolchain Manager in the Start menu.' + #13#10 +
-          'Details: %s', [Failures, ExpandConstant('{localappdata}\Rustic Game Engine\logs\toolchain-install.log')]),
-          mbError, MB_OK);
-    end;
-    if (TotalCount = 0) and AnyOptionalLanguageSelected() then
-    begin
-      WizardForm.StatusLabel.Caption := 'Selected gameplay language toolchains are already installed.';
-      WizardForm.Refresh;
-    end;
-  end;
+  if CurStep = ssPostInstall then InstallSelectedLanguageToolchains();
 end;
 
 function NeedsAddPath(Param: string): Boolean;

Engine/tools/build-windows-installer.ps1

@@ -73,6 +73,16 @@ if (-not (Test-Path -LiteralPath $iscc -PathType Leaf)) {
 
 Push-Location $workspaceRoot
 try {
+    # Compile Setup's sections and Pascal code before the expensive Cargo build.
+    # /O- prevents producing a preflight installer; only unbuilt binaries are omitted.
+    Write-Host 'Validating the Windows installer script...'
+    & $iscc '/O-' '/DInstallerPreflight=1' 'installer\RusticGameEngine.iss'
+    if ($LASTEXITCODE -ne 0) { throw "Inno Setup preflight failed with exit code $LASTEXITCODE." }
+
+    Write-Host 'Testing the toolchain manager with Windows PowerShell...'
+    & powershell -NoProfile -ExecutionPolicy Bypass -File 'tools\test-language-toolchains.ps1'
+    if ($LASTEXITCODE -ne 0) { throw "Toolchain manager tests failed with exit code $LASTEXITCODE." }
+
     Write-Host 'Building bundled Luau API host...'
     & $cargo build --locked --manifest-path 'apps/luau-host/Cargo.toml' --profile distribution --target-dir 'target'
     if ($LASTEXITCODE -ne 0) { throw "Luau host build failed with exit code $LASTEXITCODE." }