Families of
derived objects
are identified in makefiles as targets (with rules).
There may be several
DOs for the same target, but a given DO should be
the product of at most one rule.
Instances in the DO families are discriminated on the basis of the
expanded build rules, and of the dependecy graphs.
This information is saved in
configuration records
With build management, derived objects, as well as source elements, are configuration items
Reproduce a build: one-line config spec, using one
fixed label applied with apply_label.
Compare two builds: ct diffcr