Reproducer for issue with MSIX packaging of Qt desktop apps on Windows.

Qt issue: How to package a Win32 desktop app in MSIX?

Disclaimer: The author is new to MSIX packaging, so it might not be done according to "best practice".

Prerequisites

• Visual Studio 2019 or 2022 with the following workloads installed:
  • Desktop development with C++
  • Universal Windows Platform development
• Enable "Developer Mode" in Windows Settings
• Qt SDK
• CMake

Steps to reproduce

Build and startup tests:

• Ensure that the QT_ROOT_64 env. var. points to a 64bit Qt SDK installation.
• Run OpenInVisualStudio.bat to generate project files and open Visual Studio.
• Build all projects.
• Attempt to open "QtAppMSIX" project.
• Observe The code execution cannot proceed because Qt6Widgets.dll was not found error dialog.

MSIX packaging tests:

• Right click on the QtAppMSIX project and select "Publish" -> "Create App Packages..".
• In the "Select distribution method" screen, select "Sideloading" without automatic updates.
• In the "Select signing method" screen, skip package signing.
• In the "Select and configure packages" screen, select "Never" for generating app bundle.
• Press "Create" to generate MSIX installer
• Use 7-zip or similar to inspect the generated MSIX file
• Observe that the MSIX file only contain QtApp.exe, whereas required Qt DLLs are missing.