Using Powershell for Azure Devops to refer to predefined variables.

Using Powershell for Azure Devops Linux agent to refer to variables can be hard to get right essentially just use $(build.SourceBranchName) - the build.SourceBranchName is what listed in the documentation.

You can see one example given below :-

- task: PowerShell@2

      displayName: 'PowerShell contruct VersionSuffix if not Master'

      inputs:

        targetType: 'inline'

        script: |

         Write-Host "Setting up version info"

         $VersionSuffix =  'prerelease' + '.$(build.SourceBranchName).' + $(build.buildid)

         write-host "##vso[task.setvariable variable=VersionSuffix]$VersionSuffix"

         Write-Output "##vso[build.updatebuildnumber]$($env:VersionPrefix)-$VersionSuffix"

        failOnStderr: true

      condition: and(succeeded(), ne(variables['Build.SourceBranch'], 'refs/heads/master'))