Ubuntu – Variable dependency not working in YAML pipelines

I can’t figure out what am I doing wrong with variable dependencies between jobs.

I have the following pipeline, taken almost verbatim from Microsoft documentation:

trigger: none

stages:
- stage: build

  jobs:
  - job: A
    steps:
    - powershell: |
        Write-Output "##vso[task.setvariable variable=MyVar;isOutput=true]zomg"
      name: ProduceVar
    - script: echo $(ProduceVar.MyVar) # Prints out zomg.

  - job: B
    dependsOn: A
    condition: eq(dependencies.A.outputs['ProduceVar.MyVar'], 'zomg') # Fails, B does not get executed.
    variables:
      varFromA: $[ dependencies.A.outputs['ProduceVar.MyVar'] ]
    steps:
    - script: echo $(varFromA) # Does not print out the variable, it is not mapped.

The condition for job B fails with the following information:

Started: Yesterday at 16:19
Duration: 15h 33m 54s
Evaluating: eq(dependencies['A']['outputs']['ProduceVar.MyVar'], 'zomg')
Expanded: eq(Null, 'zomg')
Result: False

If I remove that check, the variable dependency is not picked up in the last script which tries to output mapped variable.

The output in this case looks like this:

Pool: Azure Pipelines
Image: ubuntu-latest
Agent: Azure Pipelines 10
Started: Yesterday at 16:22
Duration: 5s

Job preparation parameters
Variables:
  varFromA:
    Parsing expression: <dependencies.A.outputs['ProduceVar.MyVar']>
    Evaluating: dependencies['A']['outputs']['ProduceVar.MyVar']
    Expanded: Null
    Result: ''
ContinueOnError: False
TimeoutInMinutes: 60
CancelTimeoutInMinutes: 5
Expand:
  MaxConcurrency: 0
  ########## System Pipeline Decorator(s) ##########

  Begin evaluating template 'system-pre-steps.yml'
Evaluating: eq('true', variables['system.debugContext'])
Expanded: eq('true', Null)
Result: False
Evaluating: resources['repositories']['self']
Expanded: Object
Result: True
Evaluating: not(containsValue(job['steps']['*']['task']['id'], '6d15af64-176c-496d-b583-fd2ae21d4df4'))
Expanded: not(containsValue(Object, '6d15af64-176c-496d-b583-fd2ae21d4df4'))
Result: True
Evaluating: resources['repositories']['self']['checkoutOptions']
Result: Object
Evaluating: pair['key']
Result: 'fetchDepth'
Evaluating: pair['value']
Result: '1'
Evaluating: pair['key']
Result: 'lfs'
Evaluating: pair['value']
Result: 'false'
Finished evaluating template 'system-pre-steps.yml'
********************************************************************************
Template and static variable resolution complete. Final runtime YAML document:
steps:
- task: 6d15af64-176c-496d-b583-fd2ae21d4df4@1
  inputs:
    repository: self
    fetchDepth: 1
    lfs: false


  MaxConcurrency: 0

What makes this even more painful for me: I have other pipelines, where this works perfectly fine, even referencing jobs from different stages.

What silly mistake am I making here?