[WebToolsE2E][Aspire] Without installing aspire 9.1.0 and only adding dotnet9 feed, running an Azure Function with aspire project fails with error:"Newer version of .NET Aspire workload is required to run the application."

[v-sherryfan]

INSTALL STEPS

1. Clean machine: Win11 x64 23h2
2. Install VS 17.13 GA
3. Apply dotnet9 Feed

REPRO STEPS

1. Create a new project > Azure Functions > Next > .NET 8.0 lsolated (Long Term Support) > check "Enlist in .NET Aspire orchestration (Preview)" > Create
2. Open xxx.AppHost.csproj file, the Aspire.Hosting.Azure.Functions package automatically downloaded the latest 9.1 from the feed
   
3. F5

ACTUAL
The run fails with error: Newer version of .NET Aspire workload is required to run the application. Run 'dotnet workload update' to get it.

Error logs
fail: Microsoft.Extensions.Hosting.Internal.Host[11]
Hosting failed to start
Aspire.Hosting.DistributedApplicationException: Newer version of .NET Aspire workload is required to run the application. Run 'dotnet workload update' to get it.
at Aspire.Hosting.Dcp.DcpDependencyCheck.EnsureDcpVersion(DcpInfo dcpInfo) in //src/Aspire.Hosting/Dcp/DcpDependencyCheck.cs:line 160
at Aspire.Hosting.Dcp.DcpDependencyCheck.GetDcpInfoAsync(Boolean force, CancellationToken cancellationToken) in //src/Aspire.Hosting/Dcp/DcpDependencyCheck.cs:line 105
at Aspire.Hosting.Dcp.DcpDependencyCheck.GetDcpInfoAsync(Boolean force, CancellationToken cancellationToken) in //src/Aspire.Hosting/Dcp/DcpDependencyCheck.cs:line 125
at Aspire.Hosting.Dcp.DcpHost.EnsureDcpContainerRuntimeAsync(CancellationToken cancellationToken) in //src/Aspire.Hosting/Dcp/DcpHost.cs:line 64
at Aspire.Hosting.Dcp.DcpHost.StartAsync(CancellationToken cancellationToken) in //src/Aspire.Hosting/Dcp/DcpHost.cs:line 57
at Aspire.Hosting.Orchestrator.OrchestratorHostService.StartAsync(CancellationToken cancellationToken) in //src/Aspire.Hosting/Orchestrator/OrchestratorHostService.cs:line 39
at Microsoft.Extensions.Hosting.Internal.Host.b__15_1(IHostedService service, CancellationToken token)
at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List1 exceptions, Func`3 operation)

EXPECTED

1. The error message should prompt the user something like: A newer version of the Aspire templates is required to run the application. You can get it by running "dotnet new install Aspire.ProjectTemplates::9.1.0 --force".

2. If you only add dotnet9 Feed without installing aspire 9.1.0, the package version of Aspire.Hosting.Azure.Functions should be 9.0, not the latest version 9.1 from the feed.

[captainsafia]

Given that you've add the dotnet9 feed before creating the new Functions project, it appears correct that the templates are picking up the most recent version of the Aspire.Hosting.Azure.Functions package that is available on that feed, which is 9.1.0.

It seems weird that the Aspire.Hosting.AppHost version in the templates isn't picking up that latest. Have you installed the nightly templates as documented in https://github.com/dotnet/aspire/blob/main/docs/using-latest-daily.md#install-the-nightly-net-aspire-templates?

[davidfowl]

I'm trying to figure out where this error comes from. If this is something we report, we need to update the error for future versions. We can't do anything about this error in 9.0

[captainsafia]

The error seems to come from a DCP version check here:

aspire/src/Aspire.Hosting/Dcp/DcpDependencyCheck.cs

Line 135 in 26e35ad

private static void EnsureDcpVersion(DcpInfo dcpInfo)

Is the DCP version tied to the AppHost version? I'm trying to understand why DCP needs to do this check... 🤔

[davidfowl]

it wasn’t in 8 it is in 9.

[v-sherryfan]

Given that you've add the dotnet9 feed before creating the new Functions project, it appears correct that the templates are picking up the most recent version of the Aspire.Hosting.Azure.Functions package that is available on that feed, which is 9.1.0.

It seems weird that the Aspire.Hosting.AppHost version in the templates isn't picking up that latest. Have you installed the nightly templates as documented in https://github.com/dotnet/aspire/blob/main/docs/using-latest-daily.md#install-the-nightly-net-aspire-templates?

@captainsafia I did not install the 9.1.0 template, I just added the dotnet9 source, and then when I created a Function with Aspire 9.0 project, the Aspire.Hosting.AppHost package was 9.0.0, which I think is expected, but the Aspire.Hosting.Azure.Functions package selected the latest 9.1.0 from the source, which I think is unreasonable. Why do I say this, considering that when 9.1.0 is released, users will also encounter this problem when they want to create a Function with Aspire 9.0 project without installing 9.1.0 template.

[eerhardt]

The issue here is that the Azure.Functions reference is bringing in the 9.1.0 version of Aspire.Hosting, but the app is still referencing Aspire.Hosting.AppHost 9.0.0. That version needs to be updated.

#7539 is updating the error message to correctly tell the user to what to do in this case.