Summary

Currently, Build.SourcesDirectory is used to access the directory for which the code is checked out. However, this predefined variable does not work for multi-repo checkout situations. The proper variable that works for both single-checkout and multi-checkout pipelines is System.DefaultWorkingDirectory. There is also Build.Repository.LocalPath, but that does not have the desired outcome. More explanation in the Details section.

There is an additional change adding repositoryAlias to jobs.yml. This allows you to pass in the repository you want to run publish-build-assets.yml from. Otherwise, the default of self may not have Arcade. This commit encompasses those changes. Not sure if there is a doc that needs to be updated or not. Based on the docs, repositoryAlias seems to be an appropriate name.

Docs

https://learn.microsoft.com/en-us/azure/devops/pipelines/build/variables?view=azure-devops&tabs=yaml#build-variables-devops-services

Build.SourcesDirectory

Build.Repository.LocalPath

System.DefaultWorkingDirectory

Details

I found this when trying to do a multi-checkout pipeline that uses Arcade within the primary repo. The SBOM generation task would fail because it couldn't locate the artifacts folder. Therefore, I figured that I should apply this change to all files in the repo to make them work properly with multi-checkout pipelines.

At first, I tested Build.Repository.LocalPath, but there is a reason this is not the correct value to use. See the Example below.

Example

My pipeline, example.yml, is in a repository named RepoA. This pipeline pulls in a different repo, RepoB. In the yml, it would look like this:

RepoA/example.yml

...

resources:
  repositories:
  - repository: RepoB
    type: git
    name: example/RepoB
    ref: refs/heads/main

...

So, you have RepoA that references RepoB. So, when you go to do checkout (which needs to be provided in the yml because of multiple repos), it might look something like this:

RepoA/example.yml

...

steps:
- checkout: self
  path: RepoA
  displayName: Checkout RepoA
- checkout: RepoB
  path: RepoB
  workspaceRepo: true
  displayName: Checkout RepoB

...

The main thing to notice is that RepoB has workspaceRepo: true on it. What does that do? It sets the working directory for Azure Pipelines to RepoB's directory. So, here are what the paths look like for reference:

• Default: D:\a\_work\1\s (what a single repo checkout uses)
• RepoA: D:\a\_work\1\RepoA (based on setting path on checkout)
• RepoB: D:\a\_work\1\RepoB (based on setting path on checkout)

With this knowledge, how does that affect the predefined variables? Here is what you end up with (by spitting out the env vars that represent the predefined variables):

BUILD_SOURCESDIRECTORY         D:\a\_work\1\s
BUILD_REPOSITORY_LOCALPATH     D:\a\_work\1\RepoA
SYSTEM_DEFAULTWORKINGDIRECTORY D:\a\_work\1\RepoB

Since you've set the working directory using the workspaceRepo value, the intended directory is the one defined in System.DefaultWorkingDirectory. Therefore, this is the correct variable to use. Note that all 3 of these variables are set to D:\a\_work\1\s in a single-repo checkout scenario (the typical scenario).