UpToDate checker does not respect CopyBuildOutputToOutputDirectory

[rojepp]

When setting <CopyBuildOutputToOutputDirectory>false</CopyBuildOutputToOutputDirectory>, a project will rebuild on every build because UpToDate checker is looking for the non-existent assembly.
At least that's what I think is happening:

Project 'AppConfig' is not up to date. Error (0x8000FFFF).

This project is not meant to produce an assembly, just a VSTemplate.
Found this in https://github.com/Microsoft/visualfsharp (in a C# project)

[davkean]

@drewnoakes This is in reference to the legacy project system. Can you see how the new project system handles this?

[drewnoakes]

The new project system does indeed consider a project up to date when CopyBuildOutputToOutputDirectory is false.

project-system/src/Microsoft.VisualStudio.ProjectSystem.Managed/ProjectSystem/DesignTimeTargets/Microsoft.Managed.DesignTime.targets

Lines 391 to 394 in 9bac1e6

	<Target Name="CollectUpToDateCheckBuiltDesignTime" DependsOnTargets="CompileDesignTime" Returns="@(UpToDateCheckBuilt)">
	<ItemGroup>
	<!-- Assembly output, bin and obj -->
	<UpToDateCheckBuilt Condition="'$(CopyBuildOutputToOutputDirectory)' != 'false' and '$(SkipCopyBuildProduct)' != 'true'" Include="$(TargetPath)"/>

This causes the up to date check to consider the following inputs only:

obj\Debug\netstandard2.0\MyProject.dll
bin\Debug\netstandard2.0\MyProject.pdb
obj\Debug\netstandard2.0\MyProject.pdb

So this issue appear to only apply to legacy.