Just an advice coming from CDF experience (I belive people in many
other collaborations do exactly the same):
when we install locally a new version of a software product we install it
as 'new' and we never delete the version we used before - it becomes
either 'current' or 'old'. This allows the developers to have some freedom
and guarantees that things will not be screwed up completely in case of
occasional mistake.
On the other hand this problem points to that we all would be
better off if the sources were kept under control of a code management system
(i.e. CVS) in which case rebuilding of 2.00/07 would not be a problem.
Regards, Pasha.