You can download the latest binary release here. You want the vkdiag.exe link there.
VkDiag is a rudimentary vulkan diagnostics tool for Windows.
This tool was designed to check for common Windows GPU driver issues and common layer compatibility issues with RPCS3 emulator.
It was developed at the time when Windows ICD loader was fairly new and went through a bout of changes, and was fairly hard to diagnose.
It checks general system information, GPU driver registration info, and vulkan driver registration (including vulkan layers).
Please note that Linux has separate driver load mechanism, and is not supported by this tool. You may use verification and troubleshooting sections of Arch Wiki article instead.
Project is targeting legacy .NET Framework 4.8 that should be installed by default on all supported versions of Windows.
You may need to install dotnet sdk or Visual Studio Build Tools to use with some IDE (VS Code, JetBrains Raider, Visual Studio, etc).
If you have dotnet available in console, you can use dotnet build command to build the project.