Hmm. Only 2 results for a Google search on ‘”build process management” GPL’.

The MK – a Configuration Management Concept.

“The MK – a Configuration Management Concept.”
(mk-3.18.4.ps.gz, mk-3.18.4.html.gz mk-3.18.4.tar.gz)

The MK system is a UNIX software package that addresses some of the CMVC (Configuration Management and Version Control) issues. The MK system started primarily as a build facility based on the makefile generation idea. As the system was applied to the real life projects the revision system was added. At present both build and revision system work together in a specific project structure called “Shadow Tree Configuration”.

Generalities about MaK system

As has been mentioned the MaK is adapted MK software.
The adaptation extends the functionality of MK especially in following
ways:

• It suppress the locking: allows more people to work with one specified
  file at the same time.
• Enables merging of revision: logical consequence of previous point
  will be creation of different independent versions of a file by
  modifying the same revision. It
  seems to be useful to have some tool which incorporates a changes
  from one file to another or create a new file including modifications
  of two files in comparison with a given revision.
• Brings some more functions like display the content of tree, list
  directory content according the shadowing order and so on. (Most of
  this new functions has been inspirated by well known ClearCase tools.)
• Allows a comfortable build process with automatically generation of
  Makefiles with all dependencies for the ARPEGE/Aladin project.

In the following text we will use the MaK name only even in cases
that the same will be valid for the MK too.