Currently JPRT overrides MILESTONE to something that describes the build being done, with a username job id etc.

The jdk7 Hudson system needs to do the same thing.

However, MILESTONE appears to have specific values, e.g. "ea", "fcs", or "internal". And in fact some makefiles actually check for these values. Which means that the build can behave differently if MILESTONE is not one of these 3 values.
Use of RELEASE and FULL_VERSION have similar issues.

What is needed is a way to add to the version string, only for non-fcs builds, some kind of build info.

Proposal is to add a NONFCS_BUILD_INFO variable for this, whose default is empty.

Then:
ifneq ($(MILESTONE),fcs)
  Add $(NONFCS_BUILD_INFO) right after $(MILESTONE)
endif

It would need to be set to something like: NONFCS_BUILD_INFO=-nightly-re or NONFCS_BUILD_INFO=-jprt-JOBID or whatever.

The jdk and hotspot makefiles would need to change to adopt.

The current JPRT_BUILD_VERSION could be retired.

Adding some checks to make sure MILESTONE is one of a set of fixed patterns might be a good sanity check.