Manually triggering Devops pipeline with pipeline resource should use latest resource pipeline run for that branch - azure-devops

Question

I have 2 pipelines in the same repo:
Build
Deploy
The Build pipeline is declared as a pipeline resource in the Deploy pipeline:
resources:
pipelines:
- pipeline: Build
source: BuildPipelineName
trigger: true
When I run the Build pipeline, the Deploy pipeline is correctly triggered on the same branch. However, when I run the Deploy pipeline manually, it does not use the latest pipeline run from same branch.
I tried adding a couple of variations of the line below to the to the pipeline resource, but the variable does not expand:
branch: ${{ variables.Build.SourceBranchName }}
Is there any way to make this work?

Answer 1

Workaround that achieves the result I am looking for, but is not very elegant:
- ${{ if ne(variables['Build.Reason'], 'ResourceTrigger') }}:
- task: DeleteFiles#1
displayName: 'Remove downloaded artifacts from pipeline resource'
inputs:
SourceFolder: $(Pipeline.Workspace)
- task: DownloadPipelineArtifact#2
displayName: 'Download artifacts for branch'
inputs:
source: 'specific'
project: 'myProject'
pipeline: <BuildPipelineId>
runVersion: 'latestFromBranch'
runBranch: $(Build.SourceBranch)

Answer 2

For example, if I have a build pipeline named 'BuildPipelineAndDeployPipeline',
then the below YAML definition can get the latest build pipeline run from a specific branch:
resources:
pipelines:
- pipeline: BuildPipelineAndDeployPipeline
project: xxx
source: BuildPipelineAndDeployPipeline
trigger:
branches:
- main
pool:
vmImage: 'windows-latest'
steps:
- task: CmdLine#2
inputs:
script: |
echo Write your commands here
echo Hello world
echo $(resources.pipeline.BuildPipelineAndDeployPipeline.runID)