Using the 9.0.0 aspire SDK with a 9.1 preview version of the AppHost package does not detect it's installation

[davidfowl]

<Project Sdk="Microsoft.NET.Sdk;Microsoft.NET.Sdk.Publish">
	
	<Sdk Name="Aspire.AppHost.Sdk" Version="9.0.0" />

	<PropertyGroup>
		<OutputType>Exe</OutputType>
		<TargetFramework>net8.0</TargetFramework>
		<ImplicitUsings>enable</ImplicitUsings>
		<Nullable>enable</Nullable>
		<UserSecretsId>ff7ad17b-2d94-4ac9-a472-b1b236c733c7</UserSecretsId>
		<IsPublishable>true</IsPublishable>
		<NoWarn>NETSDK1023;NETSDK1057</NoWarn>
		<UseAppHost>false</UseAppHost>
	</PropertyGroup>

	<ItemGroup>
		<PackageReference Include="Aspire.Hosting.AppHost" Version="9.1.0-preview.1.25059.5" />
	</ItemGroup>
</Project>

C:\Users\davifowl\.nuget\packages\aspire.apphost.sdk\9.0.0\Sdk\Sdk.targets(39,5): warning ASPIRE002: AspireApp1.DevHost is an Aspire AppHost project but necessary dependencies aren't present. Are you missing an Aspire.Hosting.AppHost PackageReference? [C:\dev\git\AspireApps10\samples\AspireApp1.DevHost\AspireApp1.DevHost.csproj]

[joperezr]

mm wow this shouldn't be an issue. I'll investigate to try to see if I can repro as well.

[joperezr]

Looked into this. The issue here is not the mismatch between the SDK and apphost package versions, but instead the fact that your .csproj is lacking a <IsAspireHost>true</IsAspireHost>. After I add that to a project like the one you have above, I can no longer repro the issue. Given we are already addressing this as part of #6142 I'm closing this as a dupe for now. @davidfowl feel free to reopen if you think there is something special to do here.