Can't understand the difference between ResourceInclude and MergeResourceInclude in mergind resources dictionaries

[Nemonek]

Hey, I've just started experimenting with Avalonia's templated controls, and I quite immediatly ran into a problem: when trying to include my resource for the control using the following code ( as per documentation )

	<ResourceDictionary.MergedDictionaries>
		<MergeResourceInclude Source="/TemplatedControls/AudioPlayerController.axaml" />
	</ResourceDictionary.MergedDictionaries>

( All of this is inside a Windows.Resources > ResourceDictionary )
the program compiles and runs apprently without issues, but the previewer ( VS2022 ) crashes saying this:
[Error] 129904 UpdateXamlResult error details: "XamlX.XamlTransformException: Node MergeResourceInclude is unable to resolve \"avares://ImagesTo2ScreenHelper/TemplatedControls/AudioPlayerController.axaml\" path
If I instead use just ResourceInclude instead of MergeResourceInclude ( so by changing just one line ) everything works, previewer included.
Can someone explain the difference to me? Because I couldn't fine anything online

[msneijders]

In code MergeResourceInclude is marked as:

/// <summary>
/// Loads a resource dictionary from a specified URL.
/// </summary>
/// <remarks>
/// If used from the XAML code, it is merged into the parent dictionary in the compile time. 
/// When used in runtime, this type behaves like <see cref="ResourceInclude"/>.  
/// </remarks>
[RequiresUnreferencedCode(TrimmingMessages.StyleResourceIncludeRequiresUnreferenceCodeMessage)]
public class MergeResourceInclude : ResourceInclude

And according to its remarks a MergeResourceInclude defined in axaml will be handled at compile time (to give better runtime performance I'm guessing).

Cant tell why your previewer isn't compiling though. The previewer project doesnt have access to avares://ImagesTo2ScreenHelper?