[Question]:

[tnlthanzeel]

Task name

Build

Task version

No response

Environment type (Please select at least one enviroment where you face this issue)

• Self-Hosted
• Microsoft Hosted
• VMSS Pool
• Container

Azure DevOps Server type

dev.azure.com (formerly visualstudio.com)

Azure DevOps Server Version (if applicable)

No response

Operation system

ubuntu latest

Question

im trying to build my asp core 9 app on a hosted agent  which i updated to dotnet 9 from dotnet 8 today, but i get the error . it does build when i change it to dot net 8

**Error**

##[error]/usr/share/dotnet/sdk/8.0.404/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.TargetFrameworkInference.targets(166,5): Error NETSDK1045: The current .NET SDK does not support targeting .NET 9.0.  Either target .NET 8.0 or lower, or use a version of the .NET SDK that supports .NET 9.0. Download the .NET SDK from https://aka.ms/dotnet/download
/usr/share/dotnet/sdk/8.0.404/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.TargetFrameworkInference.targets(166,5): error NETSDK1045: The current .NET SDK does not support targeting .NET 9.0.  Either target .NET 8.0 or lower, or use a version of the .NET SDK that supports .NET 9.0. Download the .NET SDK from https://aka.ms/dotnet/download [/home/vsts/work/1/s/SeekNow.Account/SeekNow.Account.csproj]

**yaml file**

# ASP.NET Core (.NET Framework)
# Build and test ASP.NET Core projects targeting the full .NET Framework.
# Add steps that publish symbols, save build artifacts, and more:
# https://docs.microsoft.com/azure/devops/pipelines/languages/dotnet-core

name: $(Build.DefinitionName)_$(SourceBranchName)_$(Date:yyyyMMdd)$(Rev:.r)
trigger:
- Dev

pool:
  vmImage: 'ubuntu-latest'

variables:
  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'

steps:
    - task: NuGetToolInstaller@1

    - task: NuGetCommand@2
      displayName: 'Nuget Restore'
      inputs:
        command: restore
        restoreSolution: '$(solution)'
        # feedsToUse: 'select'
        # vstsFeed: 'GalleryERP.Feed'
    
    - task: DotNetCoreCLI@2
      displayName: 'Build'
      inputs:
        command: 'build'
        projects: '$(solution)'

[aleksandrlevochkin]

Hi @tnlthanzeel, thank you for bringing this issue up. Unfortunately, it seems that .NET 9 is not included in the ubuntu images yet: https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2204-Readme.md#net-tools

As a workaround you can use the task UseDotNet@2 that will install a specific .NET version on the hosted agent:

- task: UseDotNet@2
  inputs:
    packageType: 'sdk'
    version: '9.0.x'

Please, make sure it is placed before other .NET-related steps in your pipeline