set parameter based on another parameter - azure-devops

Question

I need to set azureSubscription property for AzurePowerShell#5 task.
The value depends on EnvName parameter, which is as follows:
- name: EnvName
displayName: Environment Name
type: string
default: dev
values:
- dev
- test
- uat
- prod
I want to do this in PowerShell in Job #1 in SetVariables task:
if (${{ parameters.EnvName }} -eq "prod") {
echo "##vso[task.setvariable variable=AzureSubscription;isOutput=true]Production Subscription"
} else {
echo "##vso[task.setvariable variable=AzureSubscription;isOutput=true]Non-Production Subscription"
}
And then assign the value to the task in Job #2:
- job: job2
dependsOn: job1
variables:
AzureSubscription: $[ dependencies.job1.outputs['SetVariables.AzureSubscription'] ]
steps:
- task: AzurePowerShell#5
inputs:
azureSubscription: '$(AzureSubscription)'
Unfortunately, this doesn't work. When executing the pipeline, I immediately get following error:
There was a resource authorization issue: "The pipeline is not valid.
Job job2: Step AzurePowerShell input ConnectedServiceNameARM
references service connection $(AzureSubscription) which could not be
found. The service connection does not exist or has not been
authorized for use. For authorization details, refer to
https://aka.ms/yamlauthz. Job job2: Step AzurePowerShell
input ConnectedServiceNameARM references service connection
$(AzureSubscription) which could not be found. The service connection
does not exist or has not been authorized for use. For authorization
details, refer to https://aka.ms/yamlauthz."
If I create AzureSubscription as a parameter instead of a runtime-computed variable, then everything works fine. But I would prefer not to, as the pipeline user shouldn't need to set its value, and doesn't need to know which value is correct.
It seems that azureSubscription property of AzurePowerShell#5 task is evaluated during compile-time. So I need to evaluate my variable (or parameter, or whatever) during compile-time too.
The only solution I came up with is to determine which job to run based on EnvName parameter, something like this:
- ${{ if eq(parameters.EnvName, 'prod') }}:
- script: echo run AzurePowerShell#5 with Production Subscription
- ${{ if ne(parameters.EnvName, 'prod') }}:
- script: echo run AzurePowerShell#5 with Non-Production Subscription
But in that case I have 2 almost identical task declarations, this complicates my YAML quite a bit.
Another solution would be to use PowerShell#2 task instead of AzurePowerShell#5. That I would also rather not do.
Is there a better way to achieve my goal?