Azure function integration: An error occurred trying to start process 'func' with working directory 'bin\Debug\net9.0\'. The system cannot find the file specified.

[DanteDeRuwe]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Aspire cannot seem to find the func command from Azure Functions Core Tools on Windows 10.

Expected Behavior

No response

Steps To Reproduce

• Repro possible with basic Aspire starter project + one azure function added with AddAzureFunctionsProject.
• Azure function core tools installed with npm i -g azure-functions-core-tools@4 --unsafe-perm true, so func is added to path (works fine in terminal)

Exceptions (if any)

 Unhandled exception: System.ComponentModel.Win32Exception (2): An error occurred trying to start process 'func' with working directory 'bin\Debug\net9.0\'. The system cannot find the file specified.
    at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
    at Microsoft.DotNet.Cli.Utils.Command.Execute(Action`1 processStarted)
    at Microsoft.DotNet.Tools.Run.RunCommand.Execute()
    at System.CommandLine.Invocation.InvocationPipeline.Invoke(ParseResult parseResult)
    at System.CommandLine.ParseResult.Invoke()
    at Microsoft.DotNet.Cli.Program.ProcessArgs(String[] args, TimeSpan startupTime, ITelemetry telemetryClient)

.NET Version info

 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.1e472b70
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19045
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\9.0.100\

.NET workloads installed:
 [android]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    35.0.24/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.android\35.0.24\WorkloadManifest.json
   Install Type:              Msi

 [aspire]
   Installation Source: SDK 9.0.100
   Manifest Version:    8.2.2/8.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.aspire\8.2.2\WorkloadManifest.json
   Install Type:              Msi

 [ios]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    18.2.9170/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.ios\18.2.9170\WorkloadManifest.json
   Install Type:              Msi

 [maccatalyst]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    18.2.9170/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.maccatalyst\18.2.9170\WorkloadManifest.json
   Install Type:              Msi

 [maui-android]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    9.0.0/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.maui\9.0.0\WorkloadManifest.json
   Install Type:              Msi

 [maui-ios]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    9.0.0/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.maui\9.0.0\WorkloadManifest.json
   Install Type:              Msi

 [maui-maccatalyst]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    9.0.0/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.maui\9.0.0\WorkloadManifest.json
   Install Type:              Msi

 [maui-windows]
   Installation Source: SDK 9.0.100, VS 17.1.31911.260
   Manifest Version:    9.0.0/9.0.100
   Manifest Path:       C:\Program Files\dotnet\sdk-manifests\9.0.100\microsoft.net.sdk.maui\9.0.0\WorkloadManifest.json
   Install Type:              Msi

Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: x64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  3.1.426 [C:\Program Files\dotnet\sdk]
  5.0.100 [C:\Program Files\dotnet\sdk]
  5.0.104 [C:\Program Files\dotnet\sdk]
  6.0.100 [C:\Program Files\dotnet\sdk]
  6.0.136 [C:\Program Files\dotnet\sdk]
  7.0.120 [C:\Program Files\dotnet\sdk]
  8.0.111 [C:\Program Files\dotnet\sdk]
  9.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 9.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  arm64 [C:\Program Files\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\arm64\InstallLocation]
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

Anything else?

AppHost package versions:

<PackageReference Include="Aspire.Hosting.AppHost" Version="9.0.0" />
        <PackageReference Include="CommunityToolkit.Aspire.Hosting.Azure.StaticWebApps" Version="9.1.0" />
        <PackageReference Include="Aspire.Hosting.Azure.Functions" Version="9.0.0-preview.5.24551.3"/>

[captainsafia]

@DanteDeRuwe Thanks for filing this issue!

Are you attempting to launch the application from Visual Studio? If so, you may need to install Azure Tooling for VS per the instructions in this page. Visual Studio doesn't resolve the local Functions host from the npm-installed directory and relies on the version provided by the VS workloads.

[DanteDeRuwe]

Hi @captainsafia, thanks for your swift response! I am running the aspire host project from the CLI with dotnet run --project <aspire-host-project-name>.

I am a Jetbrains Rider user; running it from inside that IDE gives another weird error that is documented here and also here with a comment from you

I could install VS to see if that resolves it, but I'm pretty sure it should be the case that Aspire works ootb with the dotnet CLI, no?

[captainsafia]

@DanteDeRuwe Thanks for the additional info.

The CLI issue might be the easier one to investigate since there are less moving parts there. For editor-based scenarios, the editor's Azure Functions integration comes into play when coordinating the launching of the host.

Some questions to help debug:

• What output is printed when you run func --version?
• Are you able to successfully run this project? It should be the same repro steps and runs locally as me. That will help is figure out if it is a local issue.
• Did dotnet build on your project succeed without any errors?