Permission denied when running "func start" on .NET 8 in-process Function on Ubuntu 24.04

[gabrielweyer]

• .NET SDK: 8.0.107
• Azure Function Core Tools: 4.0.5907
• Ubuntu 24.04 (WSL but same issue was experienced using GitHub Actions)

When I run func start I get the below error:

Failed to start the in-process model host. An error occurred trying to start process '/usr/lib/azure-functions-core-tools-4/in-proc8/func' with working directory '/home/gabriel/MyProjFolder/bin/output'. Permission denied

Steps taken:

1. func init MyProjFolder --worker-runtime dotnet
2. cd MyProjFolder/
3. func new --template "Http Trigger" --name MyHttpTrigger

I added FUNCTIONS_INPROC_NET8_ENABLED to local.settings.json:

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "UseDevelopmentStorage=true",
        "FUNCTIONS_WORKER_RUNTIME": "dotnet",
        "FUNCTIONS_INPROC_NET8_ENABLED": "1"
    }
}

I updated the project to target .NET 8:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.4.0" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

I'm able to run an in-process .NET 8 on Windows using the Azure Function Core Tools and on a Windows Function App.

[vfrrjq]

I have the same problem with the same versions of .NET and Azure Function Core Tools on my Mac.

Any luck funding solution to this anyone?

[mg-83]

same here on Mac M1 with OSX, did anyone found any solutions

[qng5150]

same here

[kshyju]

Thanks @gabrielweyer We will investigate and share an update on this thread. .

[mmowry-accuity]

Same here

[melvinvandenbout]

Same here with azure-functions-core-tools@4/4.0.5907.

Found a workaround which is working for me on MacOS:

chmod +x /usr/local/Cellar/azure-functions-core-tools@4/4.0.5907/in-proc8/func

I also updates this, not sure if this is required for the workaround:

`

`

[RickDMyers]

Using chmod on in-proc8/func helped get past the permissions problem. However, my visual studio code fails to attach.

Now that it compiles and runs, how do you debug?

[joserhonFA]

@kshyju I saw your PR and I was able to fix the permissions problem as well using chmod +x, but the function never starts now. When I use func host start I don't get any error message it just exits execution:

When I start the debugger (f5), it builds, but the nothing happens until I get a timeout error saying: "Failed to detect running Functions host within 60"seconds. You may want to adjust the "azureFunctions.pickProcessTimeout" setting."

This behavior is even happening with new functions I created to test .net8 using the in-process model

I have Sonoma 14.5 macOs and I'm using:

• NET SDK: 8.0.303
• Azure Function Core Tools: 4.0.5907

[essmd]

@joserhonFA i have exactly the same behavior. i got it to build successfully using chmod but i get exactly the same result and output. Like a simple build only.

• .NET SDK 8.0.400 (latest)
• Azure Function Core Tools (4.x, latest, clean download and installed)
• MacBook Pro, M3, Sonoma

[Doo-Santi]

@joserhonFA i have exactly the same behavior. i got it to build successfully using chmod but i get exactly the same result and output. Like a simple build only.

• .NET SDK 8.0.400 (latest)
• Azure Function Core Tools (4.x, latest, clean download and installed)
• MacBook Pro, M3, Sonoma

what worked for me was changing the local.settings.json file. Try having only { "IsEncrypted": false, "Values": { "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated" } }

[essmd]

@Doo-Santi We want to run the functions as „in-process“ (dotnet). Using your settings will run the functions in „isolated“ mode (dotnet-isolated). I will try it anyway, to confirm it still works in isolated mode. Thanks!

[joserhonFA]

@joserhonFA i have exactly the same behavior. i got it to build successfully using chmod but i get exactly the same result and output. Like a simple build only.

• .NET SDK 8.0.400 (latest)
• Azure Function Core Tools (4.x, latest, clean download and installed)
• MacBook Pro, M3, Sonoma

what worked for me was changing the local.settings.json file. Try having only { "IsEncrypted": false, "Values": { "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated" } }

This doesn't work. My function use the in-process model and I migrated to .net8 but still using the in-process model

[essmd]

I got it working for me, its a very inconvenient workaround but it works. Maybe it helps anybody in the meantime. I am using a MacBook Pro M3, Sonoma 14.3

1. Checkout the source code for core tools.
2. Build and publish the source (command has been copied from repo build script, but -f net8.0 was required to add due to an error)
3. Use the manually built core tools cli to run your functions project

cd your-dev-folder
gh repo clone Azure/azure-functions-core-tools
cd azure-functions-core-tools

dotnet publish src/Azure.Functions.Cli/Azure.Functions.Cli.csproj -f net8.0 --runtime osx-arm64 --output /tmp/cli

cd your-functions-project-root
/tmp/cli/func start

[RickDMyers]

I tried the suggested workaround on my MacBook Pro M2 Somona 14.6.1

It worked, I started 'tmp/cli/func start' then used the command pallet to "Debug: Attach to .Net 5+ or .NET core process" and selected the running "func" application.

To make debugging easier, I updated my Visual Studio Code Configuration and set the "Azure Function Func Cli Path" setting to "/tmp/cli/func". Visual Studio Debug with then work from "Run/Start Debugging" menu.