Azure Pipelines YAML how to use variables between jobs that have strategies - azure-devops

Question

Let's say I'm starting with this configuration that works:
jobs:
- job: ARelease
pool:
vmImage: 'Ubuntu-16.04'
steps:
- script: |
echo "##vso[task.setvariable variable=ReleaseVar;isOutput=true]1"
name: JobResult
- job: C
pool:
vmImage: 'Ubuntu-16.04'
dependsOn: ARelease
variables:
AVar: $[ dependencies.A.outputs['JobResult.ReleaseVar'] ]
steps:
- script: |
echo $(AVar)
As expected job C outputs 1.
Now let's say that I have to add a new job ADebug, which is almost identical to ARelease, so I use a strategy:
jobs:
- job: A
strategy:
matrix:
Release:
BUILD_TYPE: Release
Debug:
BUILD_TYPE: Debug
pool:
vmImage: 'Ubuntu-16.04'
steps:
- script: |
echo "##vso[task.setvariable variable=$(BUILD_TYPE)Var;isOutput=true]1"
name: JobResult
- job: C
pool:
vmImage: 'Ubuntu-16.04'
dependsOn: A
variables:
AReleaseVar: $[ dependencies.A.outputs['JobResult.ReleaseVar'] ]
ADebugVar: $[ dependencies.A.outputs['JobResult.DebugVar'] ]
steps:
- script: |
echo $(AReleaseVar)
echo $(ADebugVar)
I would expect that everything works and that I can see the outputs.. but the output is empty.
Queuing the job with diagnostics it seems that $[ dependencies.A.outputs['JobResult.ReleaseVar'] ] and $[ dependencies.A.outputs['JobResult.DebugVar'] ] evaluate to Null.
I've tried different variations to access those variables, but it always evaluates to Null.
Any idea what is the correct way?

Answer 1

https://learn.microsoft.com/en-us/azure/devops/pipelines/process/variables?view=azure-devops&tabs=yaml%2Cbatch#set-a-multi-job-output-variable
If you're setting a variable from a matrix or slice, then to reference
the variable, you have to include the name of the job as well as the
step when you access it from a downstream job.
The format is as follows: dependencies.{job}.outputs['{matrix/slice key}.{step name}.{variable name}']
In your scenario, you have Job A run with a matrix strategy (Release, Debug), and you respectively set the variable names to be ReleaseVar and DebugVar. The way to accurately access these variables is:
dependencies.A.outputs['Release.JobResult.ReleaseVar']
dependencies.A.outputs['Debug.JobResult.DebugVar']
On a side note, perhaps just use the same variable name since it you are already able to distinguish between the values based on the matrix name.