The Makefiles seem to be inconsistent in the way they find out which version they are currently building.

One way is to look into the file `ACS_VERSION` in the acs root dir.
The other way is to request the git branch name (and then storing it to `REPO_TAG` in the Makefile).

Currently this seems to be done inconsistent. Which lead to problems when the 2020OCT release was released and the file `ACS_VERSION` was forgotten to update.