Hoi tool wizards,

I have a build.sh question concerning PREVIOUSTOOLDIR.

So I've fetched src via cvs, and asked build.sh to build a fresh set
of tools for me:

 # ./build.sh -T /usr/tools -M /space/obj -D /usr/dest tools

then I've asked it to do some building...

 # ./build.sh -T /usr/tools -M /space/obj -D /usr/dest distribution

...and the first thing it does is realize that PREVIOUSTOOLDIR (= '')
is not TOOLDIR (= /usr/tools), and begins with building the tools 
again ? (Cleaning stuff, dependall, now it's sitting somewhere in gcc).

I mean, isn't that a WILD waste of cpu cycles ? (for me it's an additional
hour buildtime). On the other hand, you get bootstrapped tools which are
built by bootstrapped tools rather than by the base system, woohoo :)

I've checked the mailing lists for discussion on this, but couldn't find
anything else but errors back by the time the check was introduced.

Do I get it right that to have your tools built once you have to build
them twice ? Next time I maybe try ./build.sh ... -V PREVIOUSTOOLDIR=/usr/tools
and see what happens. 

PREVIOUSTOOLDIR is not documented in BUILDING btw. Nor in UPDATING.
Can the not-source-code-diver please get a short doc on this, please ?

Thank you in advance.

-Martin