Updating to .NET 6 causes "The host has not yet started" with VS2019/VS2022

Updating a sample to .NET 6 and updating all the dependencies to latest causes an F5 of VS2019/VS2022 to create an error “The host has not yet started”.

Output of VS2019 console

Azure Functions Core Tools
Core Tools Version:       3.0.3904 Commit hash: c345f7140a8f968c5dbc621f8a8374d8e3234206  (64-bit)
Function Runtime Version: 3.3.1.0

[2021-12-01T20:20:36.411Z] Found C:\git_ws\MaximRouiller\durablefunctions-apiscraping-dotnet\FanOutFanInCrawler\FanOutFanInCrawler.csproj. Using for user secrets file configuration.
[2021-12-01T20:20:43.322Z] A host error has occurred during startup operation '00fc43ca-ad44-4784-9f36-36f4d730e4b0'.
[2021-12-01T20:20:43.324Z] System.Private.CoreLib: Could not load type 'System.Diagnostics.DebuggerStepThroughAttribute' from assembly 'System.Runtime, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

C:\Users\marouill\AppData\Local\AzureFunctionsTools\Releases\3.30.1\cli_x64\func.exe (process 29280) exited with code -1.

Repro steps

Press F5 in VS2019/VS2022 with the following configured.

csproj file

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v3</AzureFunctionsVersion>
    <ProjectGuid>{CDA8125A-295E-4918-9FA4-70D4BEE685AA}</ProjectGuid>
    <RootNamespace>FanOutFanInCrawler</RootNamespace>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.DurableTask" Version="2.6.0" />    
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.0.13" />
    <PackageReference Include="Octokit" Version="0.50.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsDashboard": "UseDevelopmentStorage=true",
    "GitHubToken": "YOUR TOKEN HERE"
  }
}

host.json

{
  "version":  "2.0"
}

Expected behavior

Output when running from the CLI

❯ func host start
Microsoft (R) Build Engine version 17.0.0+c9eb9dd64 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

  Determining projects to restore...
  All projects are up-to-date for restore.
  FanOutFanInCrawler -> C:\git_ws\MaximRouiller\durablefunctions-apiscraping-dotnet\FanOutFanInCrawler\bin\output\FanOutFanInCrawler.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:23.24



Azure Functions Core Tools
Core Tools Version:       4.0.3971 Commit hash: d0775d487c93ebd49e9c1166d5c3c01f3c76eaaf  (64-bit)
Function Runtime Version: 4.0.1.16815

[2021-12-01T20:25:43.291Z] Found C:\git_ws\MaximRouiller\durablefunctions-apiscraping-dotnet\FanOutFanInCrawler\FanOutFanInCrawler.csproj. Using for user secrets file configuration.
[2021-12-01T20:25:48.427Z] The Dashboard setting is no longer supported. See https://aka.ms/functions-dashboard for details.

Functions:

        Orchestrator_HttpStart: [GET,POST] http://localhost:7071/api/Orchestrator_HttpStart

        GetAllRepositoriesForOrganization: activityTrigger

        GetOpenedIssues: activityTrigger

        Orchestrator: orchestrationTrigger

        SaveRepositories: activityTrigger

For detailed output, run func with --verbose flag.
[2021-12-01T20:26:05.355Z] Host lock lease acquired by instance ID '0000000000000000000000008A97D92D'.

Actual behavior

Output of VS2019 console

Azure Functions Core Tools
Core Tools Version:       3.0.3904 Commit hash: c345f7140a8f968c5dbc621f8a8374d8e3234206  (64-bit)
Function Runtime Version: 3.3.1.0

[2021-12-01T20:20:36.411Z] Found C:\git_ws\MaximRouiller\durablefunctions-apiscraping-dotnet\FanOutFanInCrawler\FanOutFanInCrawler.csproj. Using for user secrets file configuration.
[2021-12-01T20:20:43.322Z] A host error has occurred during startup operation '00fc43ca-ad44-4784-9f36-36f4d730e4b0'.
[2021-12-01T20:20:43.324Z] System.Private.CoreLib: Could not load type 'System.Diagnostics.DebuggerStepThroughAttribute' from assembly 'System.Runtime, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

C:\Users\marouill\AppData\Local\AzureFunctionsTools\Releases\3.30.1\cli_x64\func.exe (process 29280) exited with code -1.

Known workarounds

Running in the CLI to force the Azure Functions Core Tools to run with the 4.X version.

Related information

[paulbatum]

The csproj needs to have <AzureFunctionsVersion>v4</AzureFunctionsVersion> . You’ll need to run in VS 2022 (.NET 6 is not supported in VS 2019).

[DavidCubela]

I managed to run the project from the Azure Cli, however, running the same thing from inside VS 2022 does not work and shows a “The host has not yet started” error. Seems to be either the problem of missing dependency or something else.