Why is DotNetCoreCLI@2 only building Debug builds?

Why is DotNetCoreCLI@2 only building Debug builds?

In an Azure YAML build pipeline I have

trigger:
- main

pool:
  vmImage: 'ubuntu-latest'

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

steps:

- task: DotNetCoreCLI@2
  inputs:
    command: 'publish'
    publishWebProjects: false
    projects: '**/*.csproj'
    arguments: '-o $(Build.ArtifactStagingDirectory)/Output'
    zipAfterPublish: true
    modifyOutputPath: true

The DotNetCoreCLI@2 task is taken directly from the documentation

The build output indicates it's building a debug build, why is that?

Starting: DotNetCoreCLI
==============================================================================
Task         : .NET Core
Description  : Build, test, package, or publish a dotnet application, or run a custom dotnet command
Version      : 2.221.0
Author       : Microsoft Corporation
Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/build/dotnet-core-cli
==============================================================================
Info: .NET Core SDK/runtime 2.2 and 3.0 are now End of Life(EOL) and have been removed from all hosted agents. If you're using these SDK/runtimes on hosted agents, kindly upgrade to newer versions which are not EOL, or else use UseDotNet task to install the required version.
/usr/bin/dotnet publish /home/vsts/work/1/s/AppServiceTerraform/AppServiceTerraform.csproj -o /home/vsts/work/1/a/Output/AppServiceTerraform
MSBuild version 17.6.3+07e294721 for .NET
  Determining projects to restore...
  Restored /home/vsts/work/1/s/AppServiceTerraform/AppServiceTerraform.csproj (in 90 ms).
  AppServiceTerraform -> /home/vsts/work/1/s/AppServiceTerraform/bin/Debug/net6.0/AppServiceTerraform.dll
  AppServiceTerraform -> /home/vsts/work/1/a/Output/AppServiceTerraform/
Info: Azure Pipelines hosted agents have been updated and now contain .Net 5.x SDK/Runtime along with the older .Net Core version which are currently lts. Unless you have locked down a SDK version for your project(s), 5.x SDK might be picked up which might have breaking behavior as compared to previous versions. You can learn more about the breaking changes here: https://docs.microsoft.com/en-us/dotnet/core/tools/ and https://docs.microsoft.com/en-us/dotnet/core/compatibility/ . To learn about more such changes and troubleshoot, refer here: https://docs.microsoft.com/en-us/azure/devops/pipelines/tasks/build/dotnet-core-cli?view=azure-devops#troubleshooting
Finishing: DotNetCoreCLI

UPDATE Running dotnet --info on the build agent reports

Starting: Show Info
==============================================================================
Task         : PowerShell
Description  : Run a PowerShell script on Linux, macOS, or Windows
  6.0.411 [/usr/share/dotnet/sdk]
  7.0.108 [/usr/share/dotnet/sdk]
  7.0.203 [/usr/share/dotnet/sdk]
  7.0.305 [/usr/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.19 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.5 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.8 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.19 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.5 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.8 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
Finishing: Show Info

UPDATE For what it's worth I've examined the binaries in Ildasm and they do indeed appear to be debug binaries

.custom instance void [System.Runtime]System.Reflection.AssemblyConfigurationAttribute::.ctor(string) = ( 01 00 05 44 65 62 75 67 00 00 )                   // ...Debug..

You're not passing the build configuration to the task:

- task: DotNetCoreCLI@2
  inputs:
    configuration: '$(buildConfiguration)'
    ...

There's a doc note that the configuration works with pack only. I wonder why exactly, but you may need to split the pack and publish steps to use the official options.

I needed to explicitly specify the configuration in the arguments property of the task.

Although I added the task from the YAML editor task assistant, so it adding the task in a state that would perform a Debug build in a CI pipeline, and with no obvious setting to fix that seems really user unfriendly.

So as noted it is due to $(buildConfiguration) not being configured; however, to configure this there are two ways.

One is to do it via the UI in the variables tab, personally I don't recommend this as it is separate from the codebase.

The alternative would be write the variable into your pipeline similar to:

variables:
- name: buildConfiguration
  value: 'Release'

and then used like:

- task: DotNetCoreCLI@2
  inputs:
    configuration: '${{ variables.buildConfiguration}}'

Doing it this way will also let you to either set the buildConfiguration variable scoped by job or even more advanced as property of a parameter object containing your various environment information.

One other thing to confirm or assist in troubleshooting, assuming you won't use runtime expressions, can download the pipeline after completion by selecting download logs and open azuure-pipelines-expanded-yaml. This will show the entire pipeline with appropriate parameters and variables expanded...unless they are defined as runtime ones.