Use Azure DevOps pull request iteration ID as pre-release number

[kimsey0]

We use GitVersion in Mainline mode to version a number of repositories in Azure DevOps. For pull requests, we currently get version numbers like 1.2.3-PullRequest45678.X, where X is the number of commits on the feature branch we're trying to merge. We would like to have this pre-release number be monotonically increasing for each pull request, but have some tools that force-push amended commits for existing pull requests, causing conflicts.

Azure DevOps keeps an increasing iteration ID for each pull request, which is available in our build pipelines as $(System.PullRequest.PullRequestIteration). Is there any way to have it replace the pre-release number that GitVersion generates?

I can pass in the iteration as an environment variable and then override some of the assembly version variable formats, for example like /overrideconfig assembly-informational-format="{Major}.{Minor}.{Patch}-PullRequest.{env:PULL_REQUEST_ITERATION}", but this doesn't seem to extend to the value GitVersion updates the Build.BuildNumber variable with.

Is the only solution to do a bit of post-processing of the GitVersion output before setting Build.BuildNumber ourselves?

[asbjornu]

Indeed, my general recommendation is to post-process GitVersion's output. There's usually a plethora of variables I'm interested in using in my CI/CD pipelines, with GitVersion's calculated version number being one of many. I therefore tend to write a little variables.sh script which takes the version number from GitVersion as an argument and transforms that to fit the needs of the repository.