Visual Studio Build Fails for Net Core 3.0 SDK Preview 9 on Azure Devops

Question

I've been struggling with this one all weekend.

I cannot obtain a successful build for Net Core 3 SDK Preview 9 (released 4 September 2019).

I have set up a pipeline solely to:

1. Use the new SDK
2. Implement a global.json file using the new SDK
3. Use Nuget 5.x and Nuget restore to correctly obtain preview packages
4. Visual Studio Build the solution

I'm getting the following errors with the build stage (4):

Error : Unable to locate the .NET Core SDK. Check that it is installed and that the version specified in global.json (if any) matches the installed version.

Error MSB4236: The SDK 'Microsoft.NET.Sdk.Web' specified could not be found.

I was initially getting the same error during the Nuget restore stage (3) before implementing the global.json in step 2, so I know the global.json is being correctly referenced.

Pipeline YAML:

pool:
  name: Azure Pipelines
  demands:
  - msbuild
  - visualstudio

steps:
- task: UseDotNet@2
  displayName: 'Use .Net Core sdk 3.0.100-preview9-014004'
  inputs:
    version: '3.0.100-preview9-014004'
    includePreviewVersions: true

- powershell: |
   $globaljson = '{"sdk": {"version": "3.0.100-preview9-014004"}}';
   $globaljson | out-file './test.app/global.json' -Encoding UTF8
  displayName: 'Global Json'

- task: NuGetToolInstaller@1
  displayName: 'Use NuGet 5.x'
  inputs:
    versionSpec: 5.x
    checkLatest: true

- task: NuGetCommand@2
  displayName: 'NuGet restore'
  inputs:
    restoreSolution: '$(Parameters.solution)'

- task: VSBuild@1
  displayName: 'Build solution **\*.sln'
  inputs:
    solution: '$(Parameters.solution)'
    msbuildArgs: '/p:DeployOnBuild=true /p:WebPublishMethod=Package /p:PackageAsSingleFile=true /p:SkipInvalidConfigurations=true /p:PackageLocation="$(build.artifactstagingdirectory)\\"'
    platform: '$(BuildPlatform)'
    configuration: '$(BuildConfiguration)'

Answer 1

.Net Core 3.0 is finally released. You just have to install .Net Core 3.0.100 as a first step:

- task: DotNetCoreInstaller@0
  displayName: 'Install .net core 3.0.100'
  inputs:
    version: '3.0.100'

Full .yml file with test and artifacts publish. Update this 'FolderName/ProjectName.csproj' before running this.

trigger:
- master

pool:
  vmImage: 'ubuntu-latest'

variables:
  buildConfiguration: 'Release'

steps:
- task: DotNetCoreInstaller@0
  displayName: 'Install .net core 3.0.100'
  inputs:
    version: '3.0.100'

- task: DotNetCoreCLI@2
  inputs:
    command: test
    projects: '**/*Test/*.csproj'
    arguments: '--configuration $(buildConfiguration)'

- script: dotnet build --configuration $(buildConfiguration)
  displayName: 'dotnet build $(buildConfiguration)'

- task: DotNetCoreCLI@2
  displayName: 'dotnet publish --configuration $(buildConfiguration) --output $(Build.ArtifactStagingDirectory)'
  inputs:
    command: publish
    publishWebProjects: false
    projects: 'FolderName/ProjectName.csproj'
    arguments: '--configuration $(buildConfiguration) --output $(Build.ArtifactStagingDirectory)'
    zipAfterPublish: true

- task: PublishBuildArtifacts@1
  displayName: 'publish artifacts'

Answer 2

The following worked for me.

Set the following variable:

variables:
  MSBuildSDKsPath: 'C:\\hostedtoolcache\\windows\\dotnet\\sdk\\3.0.100-preview9-014004\\sdks'

Set the global json

  - task: PowerShell@2
    displayName: 'Global Json'
    inputs:
      targetType: 'inline'
      script: 'dotnet new globaljson --sdk-version 3.0.100-preview9-014004'

Also, one thing to note, I ran into issues using Nuget 5. and I used Nuget 4.7.1.

Answer 3

As suggested in the comments you need to install .net core preview 9 before you can use it.

You need to put the code below before your use statement:

- task: DotNetCoreInstaller@0
  displayName: 'Install .net core 3.0 (preview)'
  inputs:
            version: '3.0.100-preview9-014004'

Hope this helps. I use this yml to build on azure devops. I 'forgot' the global.json - added it and it worked.

Update: More from my working pipeline script

pool:
  vmImage: 'windows-latest'

variables:
  solution: '**/*.sln'
  buildPlatform: 'Any CPU'
  buildConfiguration: 'Release'
steps:
- task: DotNetCoreInstaller@0
  displayName: 'Install .net core 3.0 (preview)'
  inputs:
    version: '3.0.100-preview9-014004'

- task: NuGetToolInstaller@1

- task: NuGetCommand@2
  inputs:
    restoreSolution: '$(solution)'

azure-pipelines.yml and global.json are in the root of my project folder.