WORK IN (slow) PROGRESS

BUILD_HOME
The top most directory of all builds, regardless of stream or type.
BUILD_TYPE
The "type" of build according to out conventions: IMNYYP. Note we do not "build" S builds or R builds. They are always the result of renaming. [1]

[1]Renaming in our system always means to make a copy of the original, rename the copy, and mv the copy back to the original.