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Date: Thu, 22 Dec 1994 17:00:44 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199412220600.RAA29838@godzilla.zeta.org.au>
To: hackers@freebsd.org, roberto@blaise.ibp.fr
Subject: Re: Cleaning the compile/whatever directory before config.
Sender: hackers-owner@freebsd.org
Precedence: bulk

>Is is necessary now ? I know it used to be and wonder if we can skip it
>now... 

It may be necessary to recompile everything if an option has changed.
`make clean' after running config should be enough to ensure this.
The only difference between `make clean' after config and `rm -rf'
before config should be that first version doesn't remove obsolete
files, `version', or anything that you've changed (I like to change
the symlinks and keep old error output in the compile directory).

I usually do `cd /sys/i386/conf; cp MYCONFIG z; config z;
for i in /sys/compile/z/*; do cmp $i /sys/compile/MYCONFIG/$i; done'
to find changes and only recompile everything if important options have
changed.  This hasn't caused any problems between version 2.0 #1 (Aug 1)
and version 2.1 #468 (Dec 22).  Most of the files generated by config
are dated Aug 1.

Bruce