Example of how to pass variables between Azure DevOps stages

Azure-DevOps-Variables-Sample-yml

pool:
  vmImage: windows-latest

variables:
 - name: system.debug
   value: true

stages:
  - stage: Stage1
    jobs:
      - job: Job1
        steps:
        - checkout: none

        - pwsh:  |
            # declare the variable as standard job and stage variable
            $MyPowerShellVar = "1.2.3.4"
            write-host "Local var is $MyPowerShellVar"
            write-host "##vso[task.setvariable variable=standardvar]$MyPowerShellVar"
            write-host "##vso[task.setvariable variable=stagevar;isOutput=true]$MyPowerShellVar"
          name: myscript
          
        - pwsh:  |
            # accessing the two variable in the same job 
            Write-Host "Standard Var '$(standardvar)'"
            Write-Host "Stage Var inside the same job '$(myscript.stagevar)'"

       # to access the stage variable in a different job we need to create a local variable'alias'
       # and this job must be set to depend on the first job
      - job: Job2
        variables:
          job2alias: $[dependencies.Job1.outputs['myscript.stagevar']]
        dependsOn: Job1
        steps:
        - checkout: none
        - pwsh:  |
            Write-Host "Stage Var inside the same stage but a different job '$(job2alias)'"

   # to access the stage variable in a different stage we need to create a local variable'alias'
   # not the form is different to that used in job2 above
   # and this job must be set to depend on the first stage
  - stage: Stage2
    dependsOn: Stage1
    jobs:
      - job: Job3
        variables: # add the alias
          job3alias: $[stagedependencies.Stage1.Job1.outputs['myscript.stagevar']]
        steps:
        - checkout: none
        - pwsh:  |
            Write-Host "Stage Var inside a different stage '$(job3alias)'"