Trimming for WinUI3

[itonx (itonx)]

I've been working on a WinUI3 app and I noticed that PublishTrimmed is enabled for Release.

<PublishTrimmed Condition="'$(Configuration)' != 'Debug'">True</PublishTrimmed>

That broke the entire app because of the Reflection used in Dapper and the System.Text.Json.JsonSerializer. I have more than 30 IL warnings in my project, but there are two warnings that caught my attention:

Assembly 'Microsoft.Windows.SDK.NET' produced trim warnings. For more information see https://aka.ms/il2104
Assembly 'WinRT.Runtime' produced trim warnings. For more information see https://aka.ms/il2104

Since those assemblies are part of WinUI3 and there's no guarantee that the app works because of trimming, should I disable trimming for the app? If so, why is trimming enabled for Release?

I think I could address the IL warnings for Dapper by using a different approach and use source generation for JsonSerializer but the warnings for the SDK will remain and so the app could (or could not) fail. At this point, I think it is not worth to keep the trimming configuration unless I am missing something.

[ReginaldTang]

You should set it to False, it may sometimes trim too much

[Mahdi Hosseini (ghost1372)]

Or set trimmode to partial instead of full
<TrimMode>partial</TrimMode>

[itonx (itonx)]

In the end, I disabled it. Most third-party packages were not designed to support trimming, so chances are the application would break continuously. For small apps without many dependencies, it should be ok to keep it enabled.

[Mahdi Hosseini (ghost1372)]

So you will lose reducing application size, Native AOT and fast startup.
You can use a xml file to exclude your assembly from trimming.