Fix Workhorse version for branch and shallow clone builds

Stan Hurequested to merge
workhorse-git-describe-shallow-clone into master

What does this MR do?

Plain git describe walks history back to the nearest annotated tag, which in the GitLab monorepo is an ancient/unrelated tag. On regular branches this produced nonsensical Workhorse versions such as 11-10-0cfa69752d8-74ffd66ae-ee-415057-gecfde96bb7cc, and in a shallow clone (no reachable tags) git describe failed outright with fatal: No names found.

This changes the version logic in workhorse/Makefile to only trust git describe when HEAD is exactly at a release tag; otherwise it falls back to the VERSION file and appends the short commit SHA when a git repository is present.

Resulting main.Version:

Build source Before After
Release tag (exact match) v19.2.1-ee v19.2.1-ee (unchanged)
Branch (full clone) v12.3.0.pre-448932-g<sha> v19.3.0-pre-g<sha>
Shallow clone (--depth=1) fatal: No names found then v19.3.0-pre v19.3.0-pre-g<sha>
Tarball / no .git v19.3.0-pre v19.3.0-pre

This unblocks building Workhorse from a shallow clone.

References

Edited by Stan Hu

Merge request reports