diagnostics: collect MSI verbose install logs in diagnostic bundle

[yeelam-gordon]

Summary

Collect the MSI verbose install log in the diagnostic bundle so MSI-level failures can be diagnosed from user-uploaded logs.

Before

• wsl --update writes MSI log to %TEMP%\wsl-install-logs.txt (delete on success, keep on failure)
• Store/winget upgrade path (WslInstaller) wrote no MSI log when registry UpgradeLogFile was empty (the default)
• Diagnostic collector did not collect the MSI log

BEFORE collector output:
  wsl-install-log.txt   (5 KB)    <- high-level WSL log only, no MSI detail

After

• WslInstaller.cpp now defaults to %TEMP%\wsl-install-logs.txt (same path as wsl --update), with delete-on-success / preserve-on-failure
• Collector picks up the MSI log

All MSI upgrade paths now write to one location:

Path	Log	Cleanup
wsl --update	%TEMP%\wsl-install-logs.txt	Already did (unchanged)
Store/winget	%TEMP%\wsl-install-logs.txt	NEW (was: no log)
Both	Same file	Delete on success, preserve on failure

AFTER collector output (on failure):
  wsl-install-log.txt     (5 KB)
  wsl-install-logs.txt  (265 KB)  <- MSI verbose log with failure detail

Tested

Installed MSI with active file lock contention on WSL.lnk. Collected log contains:

Warning 1946.Property 'System.AppUserModel.ID' for shortcut 'WSL.lnk' could not be set. HRESULT 32.
Warning 1946.Property 'System.AppUserModel.ToastActivatorCLSID' for shortcut 'WSL.lnk' could not be set. HRESULT 32.

PR Checklist

• Refs: Warning 1946,Property 'System.AppUserModel.IsSstemComponent' fro shortcut 'WSL settings.lnk' could not be set. #13469, MSI installer "Warning: 1946.Property [...] could not be set." #11276, Warning 1946 from WSL update to 2.4.13.0 #12759

Changes

File	Change
src/windows/wslinstaller/exe/WslInstaller.cpp	Default log path + delete-on-success / preserve-on-failure
diagnostics/collect-wsl-logs.ps1	Collect %TEMP%\wsl-install-logs.txt

[Copilot]

Pull request overview

Adds MSI verbose installer log retention and collection to WSL’s diagnostic bundle (collect-wsl-logs.ps1) so MSI-level install/upgrade failures can be diagnosed from user-provided logs.

Changes:

• Stop auto-deleting the MSI verbose install log after a successful MSI-based update.
• Extend diagnostic bundle collection to include the MSI verbose log from %TEMP%.
• Also attempt to collect an MSI upgrade log whose path is specified via HKLM\...\Lxss\MSI\UpgradeLogFile.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/windows/common/install.cpp	Keeps the MSI verbose log (wsl-install-logs.txt) instead of deleting it on success, enabling post-install diagnostics.
diagnostics/collect-wsl-logs.ps1	Copies MSI verbose install logs into the diagnostic folder, including a registry-specified upgrade log location.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

src/windows/common/install.cpp:111

• The MSI verbose log file (wsl-install-logs.txt) is no longer deleted on successful updates because the wil::scope_exit_log cleanup was removed. This leaves the verbose MSI log behind in the user temp directory even when the update succeeds, which contradicts the intent described in the PR ("preserved on failed wsl --update") and can leave stale/possibly sensitive installer logs on disk. Consider restoring scoped cleanup and only keeping the file when the MSI exit code is non-zero (or when warnings/errors were observed during the install), so success cases don’t persist the log indefinitely.

        auto logFile = std::filesystem::temp_directory_path() / L"wsl-install-logs.txt";

        const auto exitCode = UpgradeViaMsi(downloadPath.c_str(), L"", logFile.c_str(), &MsiMessageCallback);

        if (exitCode != 0)
        {
            THROW_HR_WITH_USER_ERROR(
                HRESULT_FROM_WIN32(exitCode),
                wsl::shared::Localization::MessageUpdateFailed(exitCode) + L"\r\n" +
                    wsl::shared::Localization::MessageSeeLogFile(logFile.c_str()));
        }

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/windows/wslinstaller/exe/WslInstaller.cpp:47

• GetUpgradeLogFileLocation() returns a std::wstring, but this branch returns a std::filesystem::path via implicit conversion (weakly_canonical(path)). Please make the conversion explicit (e.g., call .wstring()), matching GetMsiPackagePath() and avoiding reliance on implicit path->string conversions.

    // A canonical path is required because msiexec doesn't like symlinks.
    return std::filesystem::weakly_canonical(path);

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[yeelam-gordon]

Addressed all review feedback in latest push:

• @ptrivedi (slash nit): Fixed to backslash for consistency ✓
• @OneBlue (duplicate copy): Removed the system temp copy line — single \C:\Users\yeelam\AppData\Local\Temp\wsl-install-logs.txt\ collection ✓
• @OneBlue (override): Resolved by removing the duplicate line ✓
• @OneBlue (UpgradeLogFile registry): Added \UpgradeLogInfo\ struct with \romRegistry\ flag — when the registry key is explicitly set, the log is always preserved (never deleted on success) ✓

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/windows/wslinstaller/exe/WslInstaller.cpp:58

• GetUpgradeLogFileLocation() returns {} on any exception (registry read failure, missing key, temp path failure), which disables MSI logging entirely. Since this PR’s goal is to always have an MSI log available for diagnostics, consider falling back to the default %TEMP%\wsl-install-logs.txt path even in the catch path (and/or when the Lxss key can’t be opened), rather than returning no log file.

catch (...)
{
    LOG_CAUGHT_EXCEPTION();
    return {};