Re: meta mode

> I use meta-mode in /etc/src-env.conf so that if (for example) a small
> change in the kernel config is made, the machine doesn't take hours
> recompiling. 

> But, from time to time, one might be required to make
> cleanworld && make cleandir (to be sure) && make clean (to be *really* sure)

Almost never (as Warner said).
I have trees that go for years without ever being cleaned.
Unless I'm collecting timing data for clean tree builds.

If you use DIRDEPS_BUILD as well as META_MODE, there can be cases where
you need the stage tree cleaned (staging is like auto-install to
DESTDIR).  The most common case is when a library has switched from
staging its headers from $STAGE_ROOT/$MACHINE/usr/include to
$STAGE_ROOT/common/usr/include (so they only get staged once), if you
don't clean out $STAGE_ROOT/$MACHINE/usr/include, builds will continue to
find headers there that should be found in
$STAGE_ROOT/common/usr/include and thus revert Makefile.depend changes.
We added a mechanism to allow triggering auto-clean of stage tree when such
changes are made.

--sjg